[llvm] [runtimes] Pass-through CLANG_RESOURCE_DIR to cmake invocations (PR #73185)

[Petr Hosek via llvm-commits]

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

That makes sense. I'd prefer having a list of passthrough variables and then include `CLANG_RESOURCE_DIR` in that list as a more generic mechanism rather than using `COMMON_CMAKE_ARGS` but I'm also fine landing this change as is and refactoring it later.

https://github.com/llvm/llvm-project/pull/73185