[llvm] Adding support in llvm-exegesis for Aarch64 for handling FPR64/128, PPR16 and ZPR128 reg class. (PR #127564)

[Aiden Grossman via llvm-commits]

https://github.com/boomanaiden154 commented:

Mostly style nits. We want to use assertions to check a value in most cases rather than the if + llvm_unreachable pattern used here as the former is more readable and canonical throughout the rest of LLVM.

https://github.com/llvm/llvm-project/pull/127564