[llvm] [ARM] Do not assume memory intrinsics specify alignment. (PR #138356)

[Harald van Dijk via llvm-commits]

hvdijk wrote:

The unguarded `*` seems to have originally come from https://reviews.llvm.org/D73874 though the code has been significantly changed in https://reviews.llvm.org/D90439, I guess I can ask the authors of both for review?

https://github.com/llvm/llvm-project/pull/138356