[llvm] [TargetParser][AArch64] Believe runtime feature detection (PR #95694)

[David Green via llvm-commits]

davemgreen wrote:

Hi - That is true, it has always been like that so shouldn't be the job of this patch to try and fix it. If you can add some testing though (hopefully to TargetParserTest.cpp) this should be OK.

https://github.com/llvm/llvm-project/pull/95694