[llvm] [MachineCopyPropagation] Recognise and delete no-op moves produced after forwarded uses (PR #129889)

[Philip Reames via llvm-commits]

preames wrote:

@steven-michaud Your description sounds a lot like the issue fixed in April, can you confirm that you are running with that patch applied?  Additionally, can you point to where in the linked bugs you narrowed it down to this patch and what you're reasoning was?  I tried skimming them, and didn't immediately find that information.  Your theory sounds somewhat reasonable, just looking for the supporting evidence to help narrow down.

https://github.com/llvm/llvm-project/pull/129889