[llvm] [polly] [IR] Enable dereferenceable-at-point semantics (PR #204795)

[Danila Malyutin via llvm-commits]

danilaml wrote:

> Making this part of GCStrategy sounds good to me.

Btw, while looking into this I've found https://github.com/llvm/llvm-project/pull/94401 that does pretty much what I wanted to implement except maybe reusing the `isGCManagedPointer` callback (I though about adding an extra one in case there is some GC that uses statepoints and allows manual frees on gc-managed pointers although I'm not aware if such thing exists or even could be cleanly represented in LLVM). Unfortunately it looks like it got stalled due to the lack of reviewers.

https://github.com/llvm/llvm-project/pull/204795