Fix cmake builds.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@65847 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
index d2fafb3..12ea2aa 100644
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@@ -7,4 +7,4 @@
 add_subdirectory(CodeGen)
 add_subdirectory(Analysis)
 add_subdirectory(Rewrite)
-add_subdirectory(Driver)
+add_subdirectory(Frontend)