pub fn reverse_postorder<'a, 'tcx>(
    body: &'a Body<'tcx>
) -> ReversePostorderIter<'a, 'tcx>Notable traits for ReversePostorderIter<'a, 'tcx>impl<'a, 'tcx> Iterator for ReversePostorderIter<'a, 'tcx> type Item = (BasicBlock, &'a BasicBlockData<'tcx>);