[clang] [llvm] [AArch64][VecLib] Add libmvec support for AArch64 targets (PR #143696)

[Paul Walker via llvm-commits]

https://github.com/paulwalker-arm commented:

I could not spot any tests for the `<2 x float>` vector functions?  Hopefully it's as easy as adding extra RUN lines to veclib-function-calls.ll and veclib-intrinsic-calls.ll. I'm thinking variants of LIBMVEC-NEON that use `-force-vector-width=2`. If this works then it's worth changing the existing LIBMVEC-NEON RUN lines to use `-force-vector-width=4` so that both variants are locked in.

https://github.com/llvm/llvm-project/pull/143696