[llvm] [AArch64][MachinePipeliner] Add pipeliner support for AArch64 (PR #79589)

[Yuta Mukai via llvm-commits]

ytmukai wrote:

I have already issued a PR for code expansion with MVE (#65609), but since existing method (renames register by move instructions) also improve performance, I thought it would be good to support it first. I intend to use this as a basis for further improvements.

Note: The following three patches that fix the existing code are required to run llvm-test-suite; I would like to submit PRs after this is accepted to include AArch64 tests to the patches.
https://github.com/ytmukai/llvm-project/tree/pipeliner-avoid-long-compile-time
https://github.com/ytmukai/llvm-project/tree/pipeliner-fix-invalid-memoperand
https://github.com/ytmukai/llvm-project/tree/pipeliner-fix-incorrect-element-insertion


https://github.com/llvm/llvm-project/pull/79589