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

[Liviu Ionescu via cfe-commits]

ilg-ul wrote:

> assuming CI passes

It passed on my Mac, let's hope that the CI will pass too.

But, not related to this PR, on my Mac, I always had several test failing:

```
Failed Tests (7):
  Clang :: Driver/baremetal.cpp
  Clang :: Driver/csky-toolchain.c
  Clang :: Driver/freebsd-include-paths.c
  Clang :: Driver/hexagon-toolchain-linux.c
  Clang :: Driver/sysroot.c
  Clang :: Frontend/warning-poison-system-directories.c
  Clang :: Index/pch-from-libclang.c


Testing Time: 844.78s
  Skipped          :    36
  Unsupported      :  3071
  Passed           : 30977
  Expectedly Failed:    24
  Failed           :     7
FAILED: tools/clang/test/CMakeFiles/check-clang /Users/ilg/Work/xpack-dev-tools-build/clang-17.0.5-1/darwin-x64/x86_64-apple-darwin23.1.0/build/llvm-17.0.5/tools/clang/test/CMakeFiles/check-clang 
```

Is this expected?


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