[llvm] AArch64: Fix mishandling subregister in orr peephole (PR #208015)

[David Green via llvm-commits]

davemgreen wrote:

Hmm. That's a shame, I was hoping you were going to say it was limited to Copies. It sounds like it would be a difficult change to make testing every backend is correct for all optimization, and doing the proper amount of testing a change like that should be given.

This looks fairly benign though. LGTM

https://github.com/llvm/llvm-project/pull/208015