strange packaging environments. The primary result of this is to expose
a (normally empty) CLANG_RESOURCE_DIR string in the autoconf and CMake builds.
This will in turn be used by a subsequent commit to Clang.
Regenerated configure and config.h.in thanks to Nick. =D
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116802 91177308-0d34-0410-b5e6-96231b3b80d8