[clang] RFC: [cmake] Export CLANG_RESOURCE_DIR in ClangConfig (PR #97197)

[Kim Gräsman via cfe-commits]

kimgr wrote:

@etcwilde 
> The path is already available through the exported clang-resource-header imported interface target

I think that one has the full path to the compiler-supplied built-in headers, not the resource dir (which is basically its parent). We could do some path mangling, but that's what burned us in the first place.


https://github.com/llvm/llvm-project/pull/97197