add header to be built by gcc 4.3 on Linux.

llvm-svn: 72158
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index 5a68346..e9ddce3 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -19,6 +19,7 @@
 #include "clang/AST/ExprObjC.h"
 #include "clang/Lex/LiteralSupport.h"
 #include "clang/Lex/Preprocessor.h"
+#include <limits>
 using namespace clang;
 
 /// getLocationOfStringLiteralByte - Return a source location that points to the