[CMake] Add missing set_output_directory after Takumi's change in r198205.

In a standalone build, Clang binaries should end up in Clang's build folder,
not LLVM's.

Xcode still has a few issues finding auxiliary tools and libraries in the
build folders. I'll fix those next.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@198328 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed