Unbreak the CMake builds following the CallGraph change.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@151952 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Index/CMakeLists.txt

@@ -3,7 +3,7 @@ set(LLVM_USED_LIBS clangBasic clangAST)
 add_clang_library(clangIndex
   ASTLocation.cpp
   Analyzer.cpp
-  CallGraph.cpp
+  GlobalCallGraph.cpp
   DeclReferenceMap.cpp
   Entity.cpp
   GlobalSelector.cpp