Minor include pruning.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@100007 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGBlocks.cpp b/lib/CodeGen/CGBlocks.cpp
index 9217859..5097341 100644
--- a/lib/CodeGen/CGBlocks.cpp
+++ b/lib/CodeGen/CGBlocks.cpp
@@ -17,6 +17,7 @@
 #include "CodeGenModule.h"
 #include "clang/AST/DeclObjC.h"
 #include "llvm/Module.h"
+#include "llvm/ADT/SmallSet.h"
 #include "llvm/Target/TargetData.h"
 #include <algorithm>