Patch for CMake to export Clang targets

[Ryan Govostes]

Hello Takumi,

I’ve attached a short patch to bug 19462, which requested that CMake create an exports .cmake file for Clang’s targets similar to the patch you applied in r201049 to create an LLVMExports.cmake file.

http://llvm.org/bugs/show_bug.cgi?id=19462

This is useful for building standalone tools that link against Clang libraries: one can just include the ClangExports.cmake file, and then CMake can automatically resolve dependencies.

However I am far from an expert at CMake or Clang’s build system. I would appreciate a sanity check that I’m not missing something.

Thanks,
Ryan