[llvm] [LoopVectorize] Add support for reverse loops in isDereferenceableAndAlignedInLoop (PR #96752)

[David Sherwood via llvm-commits]

david-arm wrote:

Rebase + addressed review comment. I ran "make check-all" downstream after rebasing and the tests look good.

https://github.com/llvm/llvm-project/pull/96752