a7f0b29733
The original change caused issues on MSVC due to a new warning thrown inside MSVC headers. That was fixed [here](https://github.com/llvm/llvm-project/pull/142019), so reapply this commit. Original description below. Instead of defining ARM ACLE intrinsics only on MSVC and guarding wrapper functions in headers with __has_builtin, universally define the intrinsics as target header builtins.