[clang] [ARM64EC] Fix compilation of intrin.h in ARM64EC mode. (PR #87717)

[Max Winkler via cfe-commits]

MaxEW707 wrote:

I put a PR with a fix, https://github.com/llvm/llvm-project/pull/112066.

This should probably go into 19.1.2 but I am familiar with that process. 
If someone with more experience in the project can give guidance there that would be appreciated :).

https://github.com/llvm/llvm-project/pull/87717