[clang] [clang][ARM][AArch64] Reapply "Define intrinsics guarded by __has_builtin on all platforms (#128222)" (PR #140910)

[Hans Wennborg via cfe-commits]

zmodem wrote:

> It looks like this commit landed, so is it safe to say I don't have revert this?

Yes, that one should unblock us, so there's no panic.

We should still fix this though.

> Is the assumption that Clang's headers provide the exact same header to intrinsic declaration mapping as MSVC's headers?

It's never going to be exact, but the idea is that they should be compatible. If the MSVC way is to write

```
#include <intrin.h>
void f() { __yield(); }
```

we want that to work with clang-cl too.

And if the include is missing, we shouldn't suggest `arm_acle.h`, because that suggestion is not compatible with MSVC.

https://github.com/llvm/llvm-project/pull/140910