[clang] [compiler-rt] [AArch64] Implement __builtin_cpu_supports, compiler-rt tests. (PR #82378)

[via cfe-commits]

bgra8 wrote:

@DanielKristofKiss do I understand correctly that you confirm the current behavior for `__builtin_cpu_supports("unsupported-features")` -- does not compile no matter the CPU --  is a `clang` defect? 

If that is the case let's file a bug to have this fixed.



https://github.com/llvm/llvm-project/pull/82378