[clang] [clang][Driver] Fix triple config loading for clang-cl (PR #111397)

[Carlo Cabrera via cfe-commits]

carlocab wrote:

> Maybe the fix is to always _ignore_ config files in clang-cl mode

I'd be fine with doing this too -- I just wasn't aware that clang-cl did not support config files (since this fact doesn't seem to be documented anywhere, unless I missed it).

https://github.com/llvm/llvm-project/pull/111397