[clang] [libclc] [clang] Add the ability to link libclc OpenCL libraries (PR #146503)

[Fraser Cormack via cfe-commits]

frasercrmck wrote:

> Agreed that this should be a resource directory thing, we made the mistake of not doing that in OpenMP until I moved it to just a normal lib.

I've got rid of the checking on LIBRARY_PATH now, thanks for your and @arsenm's input.

https://github.com/llvm/llvm-project/pull/146503