[clang] [clang][driver] Add \<executable\>/../include/c++/v1 to include path on Darwin (PR #70817)

[Liviu Ionescu via cfe-commits]

ilg-ul wrote:

I tried to write the test, but after several atempts I was not able to properly check the paths... :-(

@ldionne, do you have any suggestions on how to fix the test?


https://github.com/llvm/llvm-project/pull/70817