Add another missing include for MSVC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230912 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/IR/DiagnosticInfo.h

@@ -20,6 +20,7 @@
 #include "llvm/IR/DebugLoc.h"
 #include "llvm/IR/Module.h"
 #include "llvm/Support/Casting.h"
+#include <utility>
 
 namespace llvm {