// 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 _6: &mut std::ops::Range<u32>;
    let mut _12: std::option::Option<u32>;
    let mut _15: isize;
    let mut _17: &impl Fn(u32);
    let mut _18: (u32,);
    let _19: ();
    scope 1 {
        debug iter => _5;
        let _16: u32;
        scope 2 {
            debug x => _16;
        }
        scope 4 (inlined iter::range::<impl Iterator for std::ops::Range<u32>>::next) {
            debug self => _6;
            scope 5 (inlined <std::ops::Range<u32> as iter::range::RangeIteratorImpl>::spec_next) {
                debug self => _6;
                let mut _7: &u32;
                let mut _8: &u32;
                let mut _11: bool;
                let _13: u32;
                let mut _14: u32;
                scope 6 {
                    debug old => _13;
                    scope 7 {
                    }
                }
                scope 8 (inlined cmp::impls::<impl PartialOrd for u32>::lt) {
                    debug self => _7;
                    debug other => _8;
                    let mut _9: u32;
                    let mut _10: 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(_12);
        _6 = &mut _5;
        StorageLive(_13);
        StorageLive(_11);
        StorageLive(_7);
        _7 = &((*_6).0: u32);
        StorageLive(_8);
        _8 = &((*_6).1: u32);
        StorageLive(_9);
        _9 = (*_7);
        StorageLive(_10);
        _10 = (*_8);
        _11 = Lt(move _9, move _10);
        StorageDead(_10);
        StorageDead(_9);
        StorageDead(_8);
        StorageDead(_7);
        switchInt(move _11) -> [0: bb2, otherwise: bb3];
    }

    bb2: {
        _12 = Option::<u32>::None;
        goto -> bb5;
    }

    bb3: {
        _13 = ((*_6).0: u32);
        StorageLive(_14);
        _14 = <u32 as Step>::forward_unchecked(_13, const 1_usize) -> [return: bb4, unwind unreachable];
    }

    bb4: {
        ((*_6).0: u32) = move _14;
        StorageDead(_14);
        _12 = Option::<u32>::Some(_13);
        goto -> bb5;
    }

    bb5: {
        StorageDead(_11);
        StorageDead(_13);
        _15 = discriminant(_12);
        switchInt(move _15) -> [0: bb6, 1: bb8, otherwise: bb10];
    }

    bb6: {
        StorageDead(_12);
        StorageDead(_5);
        drop(_3) -> [return: bb7, unwind unreachable];
    }

    bb7: {
        return;
    }

    bb8: {
        _16 = ((_12 as Some).0: u32);
        StorageLive(_17);
        _17 = &_3;
        StorageLive(_18);
        _18 = (_16,);
        _19 = <impl Fn(u32) as Fn<(u32,)>>::call(move _17, move _18) -> [return: bb9, unwind unreachable];
    }

    bb9: {
        StorageDead(_18);
        StorageDead(_17);
        StorageDead(_12);
        goto -> bb1;
    }

    bb10: {
        unreachable;
    }
}