When an unlimited polymorphic descriptor is establish for an intrinsic
type spec, the `PointerNullifyIntrinsic` or `AllocatableInitIntrinsic` runtime
function is called. These functions do not initialize an addendum with a derivedType.
When the deallocation on this descriptor is performed, the runtime should not
crash if the addendum is not present. This patch updates `PointerDeallocatePolymorphic`
and `AllocatableDeallocatePolymorphic` for this use case.
Depends on D141996
Reviewed By: jeanPerier, PeteSteinfeld
Differential Revision: https://reviews.llvm.org/D142010