[clang] fix(80474): Clang crash on improper use of __array_extent (PR #94173)

[via cfe-commits]

https://github.com/Sirraide approved this pull request.

LGTM 

Though I do wonder how many other type traits are also affected by this, because at least the function below this one also doesn’t seem to check for parse errors... it would probably make sense to take a look at the rest of them too, but that can also be a separate pr.

https://github.com/llvm/llvm-project/pull/94173