// MIR for `forward_loop` after PreCodegen

fn forward_loop(_1: u32, _2: u32, _3: impl Fn(u32)) -> () {
    debug start => _1;
    debug end => _2;
    debug f => _3;
    let mut _0: ();
    let mut _4: std::ops::Range<u32>;
    let mut _5: std::ops::Range<u32>;
    let mut _9: std::option::Option<u32>;
    let mut _12: isize;
    let mut _14: &impl Fn(u32);
    let mut _15: (u32,);
    let _16: ();
    let mut _17: &mut std::ops::Range<u32>;
    scope 1 {
        debug iter => _5;
        let _13: u32;
        scope 2 {
            debug x => _13;
        }
        scope 4 (inlined iter::range::<impl Iterator for std::ops::Range<u32>>::next) {
            debug self => _17;
            scope 5 (inlined <std::ops::Range<u32> as iter::range::RangeIteratorImpl>::spec_next) {
                debug self => _17;
                let mut _8: bool;
                let _10: u32;
                let mut _11: u32;
                let mut _18: &u32;
                let mut _19: &u32;
                scope 6 {
                    debug old => _10;
                    scope 7 {
                    }
                }
                scope 8 (inlined cmp::impls::<impl PartialOrd for u32>::lt) {
                    debug self => _18;
                    debug other => _19;
                    let mut _6: u32;
                    let mut _7: u32;
                }
            }
        }
    }
    scope 3 (inlined <std::ops::Range<u32> as IntoIterator>::into_iter) {
        debug self => _4;
    }

    bb0: {
        _4 = std::ops::Range::<u32> { start: _1, end: _2 };
        StorageLive(_5);
        _5 = move _4;
        goto -> bb1;
    }

    bb1: {
        StorageLive(_9);
        StorageLive(_10);
        StorageLive(_8);
        StorageLive(_18);
        StorageLive(_19);
        StorageLive(_6);
        _6 = (_5.0: u32);
        StorageLive(_7);
        _7 = (_5.1: u32);
        _8 = Lt(move _6, move _7);
        StorageDead(_7);
        StorageDead(_6);
        switchInt(move _8) -> [0: bb2, otherwise: bb3];
    }

    bb2: {
        StorageDead(_19);
        StorageDead(_18);
        _9 = Option::<u32>::None;
        goto -> bb5;
    }

    bb3: {
        StorageDead(_19);
        StorageDead(_18);
        _10 = (_5.0: u32);
        StorageLive(_11);
        _11 = <u32 as Step>::forward_unchecked(_10, const 1_usize) -> [return: bb4, unwind: bb11];
    }

    bb4: {
        (_5.0: u32) = move _11;
        StorageDead(_11);
        _9 = Option::<u32>::Some(_10);
        goto -> bb5;
    }

    bb5: {
        StorageDead(_8);
        StorageDead(_10);
        _12 = discriminant(_9);
        switchInt(move _12) -> [0: bb6, 1: bb8, otherwise: bb10];
    }

    bb6: {
        StorageDead(_9);
        StorageDead(_5);
        drop(_3) -> [return: bb7, unwind continue];
    }

    bb7: {
        return;
    }

    bb8: {
        _13 = ((_9 as Some).0: u32);
        StorageLive(_14);
        _14 = &_3;
        StorageLive(_15);
        _15 = (_13,);
        _16 = <impl Fn(u32) as Fn<(u32,)>>::call(move _14, move _15) -> [return: bb9, unwind: bb11];
    }

    bb9: {
        StorageDead(_15);
        StorageDead(_14);
        StorageDead(_9);
        goto -> bb1;
    }

    bb10: {
        unreachable;
    }

    bb11 (cleanup): {
        drop(_3) -> [return: bb12, unwind terminate(cleanup)];
    }

    bb12 (cleanup): {
        resume;
    }
}