Function trace_raw_ptr_through_call 

pub fn trace_raw_ptr_through_call(
    tcx: TyCtxt<'_>,
    caller: DefId,
    checkpoint_block: BasicBlock,
    raw_ptr: Local,
) -> Option<PlaceKey>

Trace a raw pointer local back through call terminators to find the originating place (e.g. slice from get_unchecked).