Function transparent_deref_peel 

fn transparent_deref_peel<'tcx>(
    tcx: TyCtxt<'tcx>,
    func: &Operand<'tcx>,
) -> Option<usize>

Detect a transparent-wrapper deref whose receiver is ManuallyDrop<T> or MaybeDangling<T>, and return how many leading field-0 hops must be peeled to reach the inner T:

• ManuallyDrop<T> { value: MaybeDangling<T> } → 2 (value → MaybeDangling.0)
• MaybeDangling<P>(P) → 1.