[llvm] [GlobalOpt] Handle DL.getAllocaAddrSpace() != 0 (PR #65847)

[Matt Arsenault via llvm-commits]

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

LGTM except the test needs cleanup to avoid failing when AMDGPU isn't built 

https://github.com/llvm/llvm-project/pull/65847