[llvm] [AArch64] Eliminate Common SUBS by Reassociating Non-Constants (PR #123344)

[David Green via llvm-commits]

https://github.com/davemgreen approved this pull request.

Thanks - it might be possible to remove the other lambda too by creating the negative constant, I'm not sure if that is worth it or not.

LGTM. Thanks for the follow-up. Let me know if you are happy for this version to be submitted.

https://github.com/llvm/llvm-project/pull/123344