- // MIR for `main` before DataflowConstProp
+ // MIR for `main` after DataflowConstProp
  
  fn main() -> () {
      let mut _0: ();                      // return place in scope 0 at $DIR/ref_without_sb.rs:+0:11: +0:11
      let mut _1: i32;                     // in scope 0 at $DIR/ref_without_sb.rs:+1:9: +1:14
      let _2: ();                          // in scope 0 at $DIR/ref_without_sb.rs:+2:5: +2:15
      let mut _3: &i32;                    // in scope 0 at $DIR/ref_without_sb.rs:+2:12: +2:14
      let _4: &i32;                        // in scope 0 at $DIR/ref_without_sb.rs:+2:12: +2:14
      let _5: ();                          // in scope 0 at $DIR/ref_without_sb.rs:+4:5: +4:20
      scope 1 {
          debug a => _1;                   // in scope 1 at $DIR/ref_without_sb.rs:+1:9: +1:14
          let _6: i32;                     // in scope 1 at $DIR/ref_without_sb.rs:+6:9: +6:10
          scope 2 {
              debug b => _6;               // in scope 2 at $DIR/ref_without_sb.rs:+6:9: +6:10
          }
      }
  
      bb0: {
          StorageLive(_1);                 // scope 0 at $DIR/ref_without_sb.rs:+1:9: +1:14
          _1 = const 0_i32;                // scope 0 at $DIR/ref_without_sb.rs:+1:17: +1:18
          StorageLive(_2);                 // scope 1 at $DIR/ref_without_sb.rs:+2:5: +2:15
          StorageLive(_3);                 // scope 1 at $DIR/ref_without_sb.rs:+2:12: +2:14
          StorageLive(_4);                 // scope 1 at $DIR/ref_without_sb.rs:+2:12: +2:14
          _4 = &_1;                        // scope 1 at $DIR/ref_without_sb.rs:+2:12: +2:14
          _3 = &(*_4);                     // scope 1 at $DIR/ref_without_sb.rs:+2:12: +2:14
          _2 = escape::<i32>(move _3) -> bb1; // scope 1 at $DIR/ref_without_sb.rs:+2:5: +2:15
                                           // mir::Constant
                                           // + span: $DIR/ref_without_sb.rs:13:5: 13:11
                                           // + literal: Const { ty: for<'a> fn(&'a i32) {escape::<i32>}, val: Value(<ZST>) }
      }
  
      bb1: {
          StorageDead(_3);                 // scope 1 at $DIR/ref_without_sb.rs:+2:14: +2:15
          StorageDead(_4);                 // scope 1 at $DIR/ref_without_sb.rs:+2:15: +2:16
          StorageDead(_2);                 // scope 1 at $DIR/ref_without_sb.rs:+2:15: +2:16
          _1 = const 1_i32;                // scope 1 at $DIR/ref_without_sb.rs:+3:5: +3:10
          StorageLive(_5);                 // scope 1 at $DIR/ref_without_sb.rs:+4:5: +4:20
          _5 = some_function() -> bb2;     // scope 1 at $DIR/ref_without_sb.rs:+4:5: +4:20
                                           // mir::Constant
                                           // + span: $DIR/ref_without_sb.rs:15:5: 15:18
                                           // + literal: Const { ty: fn() {some_function}, val: Value(<ZST>) }
      }
  
      bb2: {
          StorageDead(_5);                 // scope 1 at $DIR/ref_without_sb.rs:+4:20: +4:21
          StorageLive(_6);                 // scope 1 at $DIR/ref_without_sb.rs:+6:9: +6:10
          _6 = _1;                         // scope 1 at $DIR/ref_without_sb.rs:+6:13: +6:14
          _0 = const ();                   // scope 0 at $DIR/ref_without_sb.rs:+0:11: +7:2
          StorageDead(_6);                 // scope 1 at $DIR/ref_without_sb.rs:+7:1: +7:2
          StorageDead(_1);                 // scope 0 at $DIR/ref_without_sb.rs:+7:1: +7:2
          return;                          // scope 0 at $DIR/ref_without_sb.rs:+7:2: +7:2
      }
  }