[sve][acle] Recommit https://reviews.llvm.org/D82501

The original patch was reverted in
https://github.com/llvm/llvm-project/commit/ff5ccf258e297df29f32d6b5e4fa0a7b95c44f9c
as it was missing the C tests that got accidentally missing.

This patch is a NFC of https://reviews.llvm.org/D82501, together with
the SVE ACLE tests for the C intrinsics of svreinterpret for brain
float types.