[llvm] [AArch64] New subtarget features to control ldp and stp formation, fo… (PR #66098)

[Manos Anagnostakis via llvm-commits]

manosanaggh wrote:

The regression on my test case, caught by the ci, also happens with the upstream llvm (main branch) and has nothing to do with my changes. MachineScheduler pass causes it. I may have to file a report on it.

https://github.com/llvm/llvm-project/pull/66098