[llvm] [AArch64] Disable machine-verifier for failing test, fix perf regression (PR #140005)

[Nuko Y. via llvm-commits]

yasuna-oribe wrote:

Ping @davemgreen @efriedma-quic @mikaelholmen @nikic

I've tested it locally with expensive-checks enabled, so this really shouldnt cause problems this time. I apologize if this has caused problems for others.

https://github.com/llvm/llvm-project/pull/140005