[clang] [Headers] [ARM64EC] Fix extra tokens inside intrin0.h preprocessor directive (PR #112066)

[Eli Friedman via cfe-commits]

efriedma-quic wrote:

Please add a testcase (something similar to clang/test/Headers/ms-intrin.cpp, but including intrin0.h instead of intrin.h, to catch obvious mistakes in the header).

Not sure how you're actually hitting the error you reported; the clang header directory should count as a system header, so the warning should normally be suppressed, I think.

https://github.com/llvm/llvm-project/pull/112066