[CMake] clangToolingCore requires clangLex.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@220889 91177308-0d34-0410-b5e6-96231b3b80d8
[CMake] Add dependencies on clangToolingCore.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@220890 91177308-0d34-0410-b5e6-96231b3b80d8