[C++11] Add 'override' keyword to virtual methods that override their base class.

llvm-svn: 204002
diff --git a/clang/tools/diagtool/DiagTool.h b/clang/tools/diagtool/DiagTool.h
index 93d531b..b1e69f3 100644
--- a/clang/tools/diagtool/DiagTool.h
+++ b/clang/tools/diagtool/DiagTool.h
@@ -62,7 +62,7 @@
 public:\
   CLSNAME() : DiagTool(NAME, DESC) {}\
   virtual ~CLSNAME() {}\
-  virtual int run(unsigned argc, char *argv[], llvm::raw_ostream &out);\
+  int run(unsigned argc, char *argv[], llvm::raw_ostream &out) override;\
 };\
 diagtool::RegisterDiagTool<CLSNAME> Register##CLSNAME;\
 }