[llvm] [LowerMemIntrinsics] Lower llvm.memmove to wide memory accesses (PR #100122)

[Matt Arsenault via llvm-commits]

arsenm wrote:

>  I wrote memmove tests in HIP for testing this patch; I'm considering putting them into [the HIP part of the test-suite](https://github.com/llvm/llvm-test-suite/tree/main/External/HIP), so that they are actually executed. Is there a better way to add tests for the functional correctness of the memmove lowering?

No, that's probably where they should go

https://github.com/llvm/llvm-project/pull/100122