Merging upstream version 1.70.0+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

7 files changed, 98 insertions, 127 deletions

diff --git a/compiler/rustc_borrowck/src/type_check/constraint_conversion.rs b/compiler/rustc_borrowck/src/type_check/constraint_conversion.rs
index a93561350..71eae7b27 100644
--- a/compiler/rustc_borrowck/src/type_check/constraint_conversion.rs
+++ b/compiler/rustc_borrowck/src/type_check/constraint_conversion.rs
@@ -12,7 +12,6 @@ use rustc_span::{Span, DUMMY_SP};
 
 use crate::{
     constraints::OutlivesConstraint,
-    nll::ToRegionVid,
     region_infer::TypeTest,
     type_check::{Locations, MirTypeckRegionConstraints},
     universal_regions::UniversalRegions,
@@ -198,7 +197,7 @@ impl<'a, 'tcx> ConstraintConversion<'a, 'tcx> {
 
     fn to_region_vid(&mut self, r: ty::Region<'tcx>) -> ty::RegionVid {
         if let ty::RePlaceholder(placeholder) = *r {
-            self.constraints.placeholder_region(self.infcx, placeholder).to_region_vid()
+            self.constraints.placeholder_region(self.infcx, placeholder).as_var()
         } else {
             self.universal_regions.to_region_vid(r)
         }
diff --git a/compiler/rustc_borrowck/src/type_check/input_output.rs b/compiler/rustc_borrowck/src/type_check/input_output.rs
index 717020ea5..17e702eb8 100644
--- a/compiler/rustc_borrowck/src/type_check/input_output.rs
+++ b/compiler/rustc_borrowck/src/type_check/input_output.rs
@@ -19,7 +19,7 @@ use super::{Locations, TypeChecker};
 
 impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
     /// Check explicit closure signature annotation,
-    /// e.g., `|x: FxHashMap<_, &'static u32>| ...`.
+    /// e.g., `|x: FxIndexMap<_, &'static u32>| ...`.
     #[instrument(skip(self, body), level = "debug")]
     pub(super) fn check_signature_annotation(&mut self, body: &Body<'tcx>) {
         let mir_def_id = body.source.def_id().expect_local();
diff --git a/compiler/rustc_borrowck/src/type_check/liveness/local_use_map.rs b/compiler/rustc_borrowck/src/type_check/liveness/local_use_map.rs
index 8023ef60d..2c387edfe 100644
--- a/compiler/rustc_borrowck/src/type_check/liveness/local_use_map.rs
+++ b/compiler/rustc_borrowck/src/type_check/liveness/local_use_map.rs
@@ -63,7 +63,7 @@ impl LocalUseMap {
         elements: &RegionValueElements,
         body: &Body<'_>,
     ) -> Self {
-        let nones = IndexVec::from_elem_n(None, body.local_decls.len());
+        let nones = IndexVec::from_elem(None, &body.local_decls);
         let mut local_use_map = LocalUseMap {
             first_def_at: nones.clone(),
             first_use_at: nones.clone(),
@@ -76,7 +76,7 @@ impl LocalUseMap {
         }
 
         let mut locals_with_use_data: IndexVec<Local, bool> =
-            IndexVec::from_elem_n(false, body.local_decls.len());
+            IndexVec::from_elem(false, &body.local_decls);
         live_locals.iter().for_each(|&local| locals_with_use_data[local] = true);
 
         LocalUseMapBuild { local_use_map: &mut local_use_map, elements, locals_with_use_data }
diff --git a/compiler/rustc_borrowck/src/type_check/liveness/mod.rs b/compiler/rustc_borrowck/src/type_check/liveness/mod.rs
index a411aec51..f1ad0ca55 100644
--- a/compiler/rustc_borrowck/src/type_check/liveness/mod.rs
+++ b/compiler/rustc_borrowck/src/type_check/liveness/mod.rs
@@ -11,7 +11,6 @@ use crate::{
     constraints::OutlivesConstraintSet,
     facts::{AllFacts, AllFactsExt},
     location::LocationTable,
-    nll::ToRegionVid,
     region_infer::values::RegionValueElements,
     universal_regions::UniversalRegions,
 };
@@ -80,9 +79,7 @@ fn compute_relevant_live_locals<'tcx>(
 ) -> (Vec<Local>, Vec<Local>) {
     let (boring_locals, relevant_live_locals): (Vec<_>, Vec<_>) =
         body.local_decls.iter_enumerated().partition_map(|(local, local_decl)| {
-            if tcx.all_free_regions_meet(&local_decl.ty, |r| {
-                free_regions.contains(&r.to_region_vid())
-            }) {
+            if tcx.all_free_regions_meet(&local_decl.ty, |r| free_regions.contains(&r.as_var())) {
                 Either::Left(local)
             } else {
                 Either::Right(local)
diff --git a/compiler/rustc_borrowck/src/type_check/liveness/trace.rs b/compiler/rustc_borrowck/src/type_check/liveness/trace.rs
index 473c05963..9731b10aa 100644
--- a/compiler/rustc_borrowck/src/type_check/liveness/trace.rs
+++ b/compiler/rustc_borrowck/src/type_check/liveness/trace.rs
@@ -1,4 +1,4 @@
-use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_data_structures::fx::{FxIndexMap, FxIndexSet};
 use rustc_index::bit_set::HybridBitSet;
 use rustc_index::interval::IntervalSet;
 use rustc_infer::infer::canonical::QueryRegionConstraints;
@@ -56,7 +56,7 @@ pub(super) fn trace<'mir, 'tcx>(
         elements,
         local_use_map,
         move_data,
-        drop_data: FxHashMap::default(),
+        drop_data: FxIndexMap::default(),
     };
 
     let mut results = LivenessResults::new(cx);
@@ -85,7 +85,7 @@ struct LivenessContext<'me, 'typeck, 'flow, 'tcx> {
     move_data: &'me MoveData<'tcx>,
 
     /// Cache for the results of `dropck_outlives` query.
-    drop_data: FxHashMap<Ty<'tcx>, DropData<'tcx>>,
+    drop_data: FxIndexMap<Ty<'tcx>, DropData<'tcx>>,
 
     /// Results of dataflow tracking which variables (and paths) have been
     /// initialized.
@@ -185,7 +185,7 @@ impl<'me, 'typeck, 'flow, 'tcx> LivenessResults<'me, 'typeck, 'flow, 'tcx> {
     fn add_extra_drop_facts(
         &mut self,
         drop_used: Vec<(Local, Location)>,
-        relevant_live_locals: FxHashSet<Local>,
+        relevant_live_locals: FxIndexSet<Local>,
     ) {
         let locations = IntervalSet::new(self.cx.elements.num_points());
 
@@ -435,8 +435,7 @@ impl<'me, 'typeck, 'flow, 'tcx> LivenessResults<'me, 'typeck, 'flow, 'tcx> {
         //
         // What we *actually* generate is a store to a temporary
         // for the call (`TMP = call()...`) and then a
-        // `DropAndReplace` to swap that with `X`
-        // (`DropAndReplace` has very particular semantics).
+        // `Drop(X)` followed by `X = TMP`  to swap that with `X`.
     }
 }
 
diff --git a/compiler/rustc_borrowck/src/type_check/mod.rs b/compiler/rustc_borrowck/src/type_check/mod.rs
index a49da3da6..2f10e30be 100644
--- a/compiler/rustc_borrowck/src/type_check/mod.rs
+++ b/compiler/rustc_borrowck/src/type_check/mod.rs
@@ -9,13 +9,12 @@ use either::Either;
 
 use hir::OpaqueTyOrigin;
 use rustc_data_structures::frozen::Frozen;
-use rustc_data_structures::fx::{FxHashMap, FxHashSet};
-use rustc_data_structures::vec_map::VecMap;
+use rustc_data_structures::fx::{FxIndexMap, FxIndexSet};
 use rustc_hir as hir;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::LocalDefId;
 use rustc_hir::lang_items::LangItem;
-use rustc_index::vec::{Idx, IndexVec};
+use rustc_index::vec::{IndexSlice, IndexVec};
 use rustc_infer::infer::canonical::QueryRegionConstraints;
 use rustc_infer::infer::outlives::env::RegionBoundPairs;
 use rustc_infer::infer::region_constraints::RegionConstraintData;
@@ -36,8 +35,9 @@ use rustc_middle::ty::{
     OpaqueHiddenType, OpaqueTypeKey, RegionVid, Ty, TyCtxt, UserType, UserTypeAnnotationIndex,
 };
 use rustc_span::def_id::CRATE_DEF_ID;
+use rustc_span::symbol::sym;
 use rustc_span::{Span, DUMMY_SP};
-use rustc_target::abi::VariantIdx;
+use rustc_target::abi::{FieldIdx, FIRST_VARIANT};
 use rustc_trait_selection::traits::query::type_op::custom::scrape_region_constraints;
 use rustc_trait_selection::traits::query::type_op::custom::CustomTypeOp;
 use rustc_trait_selection::traits::query::type_op::{TypeOp, TypeOpOutput};
@@ -56,7 +56,6 @@ use crate::{
     facts::AllFacts,
     location::LocationTable,
     member_constraints::MemberConstraintSet,
-    nll::ToRegionVid,
     path_utils,
     region_infer::values::{
         LivenessValues, PlaceholderIndex, PlaceholderIndices, RegionValueElements,
@@ -126,7 +125,7 @@ pub(crate) fn type_check<'mir, 'tcx>(
     infcx: &BorrowckInferCtxt<'_, 'tcx>,
     param_env: ty::ParamEnv<'tcx>,
     body: &Body<'tcx>,
-    promoted: &IndexVec<Promoted, Body<'tcx>>,
+    promoted: &IndexSlice<Promoted, Body<'tcx>>,
     universal_regions: &Rc<UniversalRegions<'tcx>>,
     location_table: &LocationTable,
     borrow_set: &BorrowSet<'tcx>,
@@ -145,7 +144,7 @@ pub(crate) fn type_check<'mir, 'tcx>(
         outlives_constraints: OutlivesConstraintSet::default(),
         member_constraints: MemberConstraintSet::default(),
         type_tests: Vec::default(),
-        universe_causes: FxHashMap::default(),
+        universe_causes: FxIndexMap::default(),
     };
 
     let CreateResult {
@@ -293,7 +292,7 @@ enum FieldAccessError {
 /// is a problem.
 struct TypeVerifier<'a, 'b, 'tcx> {
     cx: &'a mut TypeChecker<'b, 'tcx>,
-    promoted: &'b IndexVec<Promoted, Body<'tcx>>,
+    promoted: &'b IndexSlice<Promoted, Body<'tcx>>,
     last_span: Span,
     errors_reported: bool,
 }
@@ -494,7 +493,7 @@ impl<'a, 'b, 'tcx> Visitor<'tcx> for TypeVerifier<'a, 'b, 'tcx> {
 impl<'a, 'b, 'tcx> TypeVerifier<'a, 'b, 'tcx> {
     fn new(
         cx: &'a mut TypeChecker<'b, 'tcx>,
-        promoted: &'b IndexVec<Promoted, Body<'tcx>>,
+        promoted: &'b IndexSlice<Promoted, Body<'tcx>>,
     ) -> Self {
         TypeVerifier { promoted, last_span: cx.body.span, cx, errors_reported: false }
     }
@@ -772,11 +771,14 @@ impl<'a, 'b, 'tcx> TypeVerifier<'a, 'b, 'tcx> {
 
         match context {
             PlaceContext::MutatingUse(_) => ty::Invariant,
-            PlaceContext::NonUse(StorageDead | StorageLive | VarDebugInfo) => ty::Invariant,
+            PlaceContext::NonUse(StorageDead | StorageLive | PlaceMention | VarDebugInfo) => {
+                ty::Invariant
+            }
             PlaceContext::NonMutatingUse(
-                Inspect | Copy | Move | SharedBorrow | ShallowBorrow | UniqueBorrow | AddressOf
-                | Projection,
-            ) => ty::Covariant,
+                Inspect | Copy | Move | SharedBorrow | ShallowBorrow | AddressOf | Projection
+            ) => {
+                ty::Covariant
+            },
             PlaceContext::NonUse(AscribeUserTy) => ty::Covariant,
         }
     }
@@ -785,7 +787,7 @@ impl<'a, 'b, 'tcx> TypeVerifier<'a, 'b, 'tcx> {
         &mut self,
         parent: &dyn fmt::Debug,
         base_ty: PlaceTy<'tcx>,
-        field: Field,
+        field: FieldIdx,
         location: Location,
     ) -> Result<Ty<'tcx>, FieldAccessError> {
         let tcx = self.tcx();
@@ -811,7 +813,7 @@ impl<'a, 'b, 'tcx> TypeVerifier<'a, 'b, 'tcx> {
             },
             PlaceTy { ty, variant_index: None } => match *ty.kind() {
                 ty::Adt(adt_def, substs) if !adt_def.is_enum() => {
-                    (adt_def.variant(VariantIdx::new(0)), substs)
+                    (adt_def.variant(FIRST_VARIANT), substs)
                 }
                 ty::Closure(_, substs) => {
                     return match substs
@@ -853,7 +855,7 @@ impl<'a, 'b, 'tcx> TypeVerifier<'a, 'b, 'tcx> {
             },
         };
 
-        if let Some(field) = variant.fields.get(field.index()) {
+        if let Some(field) = variant.fields.get(field) {
             Ok(self.cx.normalize(field.ty(tcx, substs), location))
         } else {
             Err(FieldAccessError::OutOfRange { field_count: variant.fields.len() })
@@ -875,7 +877,7 @@ struct TypeChecker<'a, 'tcx> {
     user_type_annotations: &'a CanonicalUserTypeAnnotations<'tcx>,
     region_bound_pairs: &'a RegionBoundPairs<'tcx>,
     implicit_region_bound: ty::Region<'tcx>,
-    reported_errors: FxHashSet<(Ty<'tcx>, Span)>,
+    reported_errors: FxIndexSet<(Ty<'tcx>, Span)>,
     borrowck_context: &'a mut BorrowCheckContext<'a, 'tcx>,
 }
 
@@ -892,7 +894,7 @@ pub(crate) struct MirTypeckResults<'tcx> {
     pub(crate) constraints: MirTypeckRegionConstraints<'tcx>,
     pub(crate) universal_region_relations: Frozen<UniversalRegionRelations<'tcx>>,
     pub(crate) opaque_type_values:
-        VecMap<OpaqueTypeKey<'tcx>, (OpaqueHiddenType<'tcx>, OpaqueTyOrigin)>,
+        FxIndexMap<OpaqueTypeKey<'tcx>, (OpaqueHiddenType<'tcx>, OpaqueTyOrigin)>,
 }
 
 /// A collection of region constraints that must be satisfied for the
@@ -925,7 +927,7 @@ pub(crate) struct MirTypeckRegionConstraints<'tcx> {
 
     pub(crate) member_constraints: MemberConstraintSet<'tcx, RegionVid>,
 
-    pub(crate) universe_causes: FxHashMap<ty::UniverseIndex, UniverseInfo<'tcx>>,
+    pub(crate) universe_causes: FxIndexMap<ty::UniverseIndex, UniverseInfo<'tcx>>,
 
     pub(crate) type_tests: Vec<TypeTest<'tcx>>,
 }
@@ -1178,10 +1180,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                         }
                     }
                     Some(l)
-                        if matches!(
-                            body.local_decls[l].local_info,
-                            Some(box LocalInfo::AggregateTemp)
-                        ) =>
+                        if matches!(body.local_decls[l].local_info(), LocalInfo::AggregateTemp) =>
                     {
                         ConstraintCategory::Usage
                     }
@@ -1282,6 +1281,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
             | StatementKind::Retag { .. }
             | StatementKind::Coverage(..)
             | StatementKind::ConstEvalCounter
+            | StatementKind::PlaceMention(..)
             | StatementKind::Nop => {}
             StatementKind::Deinit(..) | StatementKind::SetDiscriminant { .. } => {
                 bug!("Statement not allowed in this MIR phase")
@@ -1301,7 +1301,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         match &term.kind {
             TerminatorKind::Goto { .. }
             | TerminatorKind::Resume
-            | TerminatorKind::Abort
+            | TerminatorKind::Terminate
             | TerminatorKind::Return
             | TerminatorKind::GeneratorDrop
             | TerminatorKind::Unreachable
@@ -1312,24 +1312,6 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                 // no checks needed for these
             }
 
-            TerminatorKind::DropAndReplace { place, value, target: _, unwind: _ } => {
-                let place_ty = place.ty(body, tcx).ty;
-                let rv_ty = value.ty(body, tcx);
-
-                let locations = term_location.to_locations();
-                if let Err(terr) =
-                    self.sub_types(rv_ty, place_ty, locations, ConstraintCategory::Assignment)
-                {
-                    span_mirbug!(
-                        self,
-                        term,
-                        "bad DropAndReplace ({:?} = {:?}): {:?}",
-                        place_ty,
-                        rv_ty,
-                        terr
-                    );
-                }
-            }
             TerminatorKind::SwitchInt { discr, .. } => {
                 self.check_operand(discr, term_location);
 
@@ -1357,20 +1339,13 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                 };
                 let (sig, map) = tcx.replace_late_bound_regions(sig, |br| {
                     use crate::renumber::{BoundRegionInfo, RegionCtxt};
-                    use rustc_span::Symbol;
 
                     let region_ctxt_fn = || {
                         let reg_info = match br.kind {
-                            ty::BoundRegionKind::BrAnon(_, Some(span)) => {
-                                BoundRegionInfo::Span(span)
-                            }
-                            ty::BoundRegionKind::BrAnon(..) => {
-                                BoundRegionInfo::Name(Symbol::intern("anon"))
-                            }
+                            ty::BoundRegionKind::BrAnon(Some(span)) => BoundRegionInfo::Span(span),
+                            ty::BoundRegionKind::BrAnon(..) => BoundRegionInfo::Name(sym::anon),
                             ty::BoundRegionKind::BrNamed(_, name) => BoundRegionInfo::Name(name),
-                            ty::BoundRegionKind::BrEnv => {
-                                BoundRegionInfo::Name(Symbol::intern("env"))
-                            }
+                            ty::BoundRegionKind::BrEnv => BoundRegionInfo::Name(sym::env),
                         };
 
                         RegionCtxt::LateBound(reg_info)
@@ -1603,7 +1578,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                     span_mirbug!(self, block_data, "resume on non-cleanup block!")
                 }
             }
-            TerminatorKind::Abort => {
+            TerminatorKind::Terminate => {
                 if !is_cleanup {
                     span_mirbug!(self, block_data, "abort on non-cleanup block!")
                 }
@@ -1629,26 +1604,15 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
             }
             TerminatorKind::Unreachable => {}
             TerminatorKind::Drop { target, unwind, .. }
-            | TerminatorKind::DropAndReplace { target, unwind, .. }
-            | TerminatorKind::Assert { target, cleanup: unwind, .. } => {
+            | TerminatorKind::Assert { target, unwind, .. } => {
                 self.assert_iscleanup(body, block_data, target, is_cleanup);
-                if let Some(unwind) = unwind {
-                    if is_cleanup {
-                        span_mirbug!(self, block_data, "unwind on cleanup block")
-                    }
-                    self.assert_iscleanup(body, block_data, unwind, true);
-                }
+                self.assert_iscleanup_unwind(body, block_data, unwind, is_cleanup);
             }
-            TerminatorKind::Call { ref target, cleanup, .. } => {
+            TerminatorKind::Call { ref target, unwind, .. } => {
                 if let &Some(target) = target {
                     self.assert_iscleanup(body, block_data, target, is_cleanup);
                 }
-                if let Some(cleanup) = cleanup {
-                    if is_cleanup {
-                        span_mirbug!(self, block_data, "cleanup on cleanup block")
-                    }
-                    self.assert_iscleanup(body, block_data, cleanup, true);
-                }
+                self.assert_iscleanup_unwind(body, block_data, unwind, is_cleanup);
             }
             TerminatorKind::FalseEdge { real_target, imaginary_target } => {
                 self.assert_iscleanup(body, block_data, real_target, is_cleanup);
@@ -1656,23 +1620,13 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
             }
             TerminatorKind::FalseUnwind { real_target, unwind } => {
                 self.assert_iscleanup(body, block_data, real_target, is_cleanup);
-                if let Some(unwind) = unwind {
-                    if is_cleanup {
-                        span_mirbug!(self, block_data, "cleanup in cleanup block via false unwind");
-                    }
-                    self.assert_iscleanup(body, block_data, unwind, true);
-                }
+                self.assert_iscleanup_unwind(body, block_data, unwind, is_cleanup);
             }
-            TerminatorKind::InlineAsm { destination, cleanup, .. } => {
+            TerminatorKind::InlineAsm { destination, unwind, .. } => {
                 if let Some(target) = destination {
                     self.assert_iscleanup(body, block_data, target, is_cleanup);
                 }
-                if let Some(cleanup) = cleanup {
-                    if is_cleanup {
-                        span_mirbug!(self, block_data, "cleanup on cleanup block")
-                    }
-                    self.assert_iscleanup(body, block_data, cleanup, true);
-                }
+                self.assert_iscleanup_unwind(body, block_data, unwind, is_cleanup);
             }
         }
     }
@@ -1689,6 +1643,29 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         }
     }
 
+    fn assert_iscleanup_unwind(
+        &mut self,
+        body: &Body<'tcx>,
+        ctxt: &dyn fmt::Debug,
+        unwind: UnwindAction,
+        is_cleanup: bool,
+    ) {
+        match unwind {
+            UnwindAction::Cleanup(unwind) => {
+                if is_cleanup {
+                    span_mirbug!(self, ctxt, "unwind on cleanup block")
+                }
+                self.assert_iscleanup(body, ctxt, unwind, true);
+            }
+            UnwindAction::Continue => {
+                if is_cleanup {
+                    span_mirbug!(self, ctxt, "unwind on cleanup block")
+                }
+            }
+            UnwindAction::Unreachable | UnwindAction::Terminate => (),
+        }
+    }
+
     fn check_local(&mut self, body: &Body<'tcx>, local: Local, local_decl: &LocalDecl<'tcx>) {
         match body.local_kind(local) {
             LocalKind::ReturnPointer | LocalKind::Arg => {
@@ -1700,7 +1677,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                 // - maybe we should make that a warning.
                 return;
             }
-            LocalKind::Var | LocalKind::Temp => {}
+            LocalKind::Temp => {}
         }
 
         // When `unsized_fn_params` or `unsized_locals` is enabled, only function calls
@@ -1736,7 +1713,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
     fn aggregate_field_ty(
         &mut self,
         ak: &AggregateKind<'tcx>,
-        field_index: usize,
+        field_index: FieldIdx,
         location: Location,
     ) -> Result<Ty<'tcx>, FieldAccessError> {
         let tcx = self.tcx();
@@ -1753,7 +1730,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                 }
             }
             AggregateKind::Closure(_, substs) => {
-                match substs.as_closure().upvar_tys().nth(field_index) {
+                match substs.as_closure().upvar_tys().nth(field_index.as_usize()) {
                     Some(ty) => Ok(ty),
                     None => Err(FieldAccessError::OutOfRange {
                         field_count: substs.as_closure().upvar_tys().count(),
@@ -1764,7 +1741,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                 // It doesn't make sense to look at a field beyond the prefix;
                 // these require a variant index, and are not initialized in
                 // aggregate rvalues.
-                match substs.as_generator().prefix_tys().nth(field_index) {
+                match substs.as_generator().prefix_tys().nth(field_index.as_usize()) {
                     Some(ty) => Ok(ty),
                     None => Err(FieldAccessError::OutOfRange {
                         field_count: substs.as_generator().prefix_tys().count(),
@@ -2242,6 +2219,13 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                             }
                         }
                     }
+                    CastKind::Transmute => {
+                        span_mirbug!(
+                            self,
+                            rvalue,
+                            "Unexpected CastKind::Transmute, which is not permitted in Analysis MIR",
+                        );
+                    }
                 }
             }
 
@@ -2362,7 +2346,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         body: &Body<'tcx>,
         rvalue: &Rvalue<'tcx>,
         aggregate_kind: &AggregateKind<'tcx>,
-        operands: &[Operand<'tcx>],
+        operands: &IndexSlice<FieldIdx, Operand<'tcx>>,
         location: Location,
     ) {
         let tcx = self.tcx();
@@ -2374,7 +2358,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
             return;
         }
 
-        for (i, operand) in operands.iter().enumerate() {
+        for (i, operand) in operands.iter_enumerated() {
             let field_ty = match self.aggregate_field_ty(aggregate_kind, i, location) {
                 Ok(field_ty) => field_ty,
                 Err(FieldAccessError::OutOfRange { field_count }) => {
@@ -2382,8 +2366,8 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                         self,
                         rvalue,
                         "accessed field #{} but variant only has {}",
-                        i,
-                        field_count
+                        i.as_u32(),
+                        field_count,
                     );
                     continue;
                 }
@@ -2435,7 +2419,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         if let Some(all_facts) = all_facts {
             let _prof_timer = self.infcx.tcx.prof.generic_activity("polonius_fact_generation");
             if let Some(borrow_index) = borrow_set.get_index_of(&location) {
-                let region_vid = borrow_region.to_region_vid();
+                let region_vid = borrow_region.as_var();
                 all_facts.loan_issued_at.push((
                     region_vid,
                     borrow_index,
@@ -2481,8 +2465,8 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                     match base_ty.kind() {
                         ty::Ref(ref_region, _, mutbl) => {
                             constraints.outlives_constraints.push(OutlivesConstraint {
-                                sup: ref_region.to_region_vid(),
-                                sub: borrow_region.to_region_vid(),
+                                sup: ref_region.as_var(),
+                                sub: borrow_region.as_var(),
                                 locations: location.to_locations(),
                                 span: location.to_locations().span(body),
                                 category,
@@ -2612,7 +2596,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                 self.implicit_region_bound,
                 self.param_env,
                 location.to_locations(),
-                DUMMY_SP,                   // irrelevant; will be overrided.
+                DUMMY_SP,                   // irrelevant; will be overridden.
                 ConstraintCategory::Boring, // same as above.
                 &mut self.borrowck_context.constraints,
             )
diff --git a/compiler/rustc_borrowck/src/type_check/relate_tys.rs b/compiler/rustc_borrowck/src/type_check/relate_tys.rs
index d96372fb9..7e6d17ec3 100644
--- a/compiler/rustc_borrowck/src/type_check/relate_tys.rs
+++ b/compiler/rustc_borrowck/src/type_check/relate_tys.rs
@@ -4,6 +4,7 @@ use rustc_infer::traits::PredicateObligations;
 use rustc_middle::mir::ConstraintCategory;
 use rustc_middle::ty::relate::TypeRelation;
 use rustc_middle::ty::{self, Ty};
+use rustc_span::symbol::sym;
 use rustc_span::{Span, Symbol};
 use rustc_trait_selection::traits::query::Fallible;
 
@@ -123,18 +124,17 @@ impl<'tcx> TypeRelatingDelegate<'tcx> for NllTypeRelatingDelegate<'_, '_, 'tcx>
             .constraints
             .placeholder_region(self.type_checker.infcx, placeholder);
 
-        let reg_info = match placeholder.name {
-            ty::BoundRegionKind::BrAnon(_, Some(span)) => BoundRegionInfo::Span(span),
-            ty::BoundRegionKind::BrAnon(..) => BoundRegionInfo::Name(Symbol::intern("anon")),
+        let reg_info = match placeholder.bound.kind {
+            ty::BoundRegionKind::BrAnon(Some(span)) => BoundRegionInfo::Span(span),
+            ty::BoundRegionKind::BrAnon(..) => BoundRegionInfo::Name(sym::anon),
             ty::BoundRegionKind::BrNamed(_, name) => BoundRegionInfo::Name(name),
-            ty::BoundRegionKind::BrEnv => BoundRegionInfo::Name(Symbol::intern("env")),
+            ty::BoundRegionKind::BrEnv => BoundRegionInfo::Name(sym::env),
         };
 
-        let reg_var =
-            reg.as_var().unwrap_or_else(|| bug!("expected region {:?} to be of kind ReVar", reg));
-        let mut var_to_origin = self.type_checker.infcx.reg_var_to_origin.borrow_mut();
-        let prev = var_to_origin.insert(reg_var, RegionCtxt::Placeholder(reg_info));
-        assert!(matches!(prev, None));
+        if cfg!(debug_assertions) && !self.type_checker.infcx.inside_canonicalization_ctxt() {
+            let mut var_to_origin = self.type_checker.infcx.reg_var_to_origin.borrow_mut();
+            var_to_origin.insert(reg.as_var(), RegionCtxt::Placeholder(reg_info));
+        }
 
         reg
     }
@@ -146,17 +146,9 @@ impl<'tcx> TypeRelatingDelegate<'tcx> for NllTypeRelatingDelegate<'_, '_, 'tcx>
             universe,
         );
 
-        let reg_var =
-            reg.as_var().unwrap_or_else(|| bug!("expected region {:?} to be of kind ReVar", reg));
-
-        if cfg!(debug_assertions) {
+        if cfg!(debug_assertions) && !self.type_checker.infcx.inside_canonicalization_ctxt() {
             let mut var_to_origin = self.type_checker.infcx.reg_var_to_origin.borrow_mut();
-            let prev = var_to_origin.insert(reg_var, RegionCtxt::Existential(None));
-
-            // It only makes sense to track region vars in non-canonicalization contexts. If this
-            // ever changes we either want to get rid of `BorrowckInferContext::reg_var_to_origin`
-            // or modify how we track nll region vars for that map.
-            assert!(matches!(prev, None));
+            var_to_origin.insert(reg.as_var(), RegionCtxt::Existential(None));
         }
 
         reg