[libc-commits] [libc] [libc] Only use COMPILER_RESOURCE_DIR if available (PR #97465)

[Petr Hosek via libc-commits]

petrhosek wrote:

This should address the build error on full build GCC builder: https://lab.llvm.org/buildbot/#/builders/131/builds/1289

https://github.com/llvm/llvm-project/pull/97465