[llvm] [AArch64] Split Ampere1Write_Arith into rr/ri and rs/rx InstRWs. (PR #66384)

[Philipp Tomsich via llvm-commits]

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

LGTM.

Thanks for taking the time to address this issue and adding the test case... we had this issue on our list (a colleague had filed the ticked), but it would have been a while until this would have bubbled to the top of the priority queue.

https://github.com/llvm/llvm-project/pull/66384