[llvm] [AMDGPU] Restrict promote alloca on pointers across address spaces (PR #119762)

[Shilei Tian via llvm-commits]

https://github.com/shiltian requested changes to this pull request.

> Casting the pointer across these address spaces is undefined behavior.

Are you sure?

I don't think this PR is right. It probably just treats the symptoms instead of the root cause of the assertion.

https://github.com/llvm/llvm-project/pull/119762