Replace OVERRIDE->override and FINAL->final since we now require C++11.

src/typing.h

Index: src/typing.h
diff --git a/src/typing.h b/src/typing.h
index 34649775fb8231d79b012ba00209d6ef88e6f789..f9442e6007a4b27998019c4e7d97cb946be010d4 100644
--- a/src/typing.h
+++ b/src/typing.h
@@ -69,10 +69,10 @@ class AstTyper: public AstVisitor {
            var->IsParameter() ? parameter_index(var->index()) : kNoVar;
   }
 
-  void VisitDeclarations(ZoneList<Declaration*>* declarations) OVERRIDE;
-  void VisitStatements(ZoneList<Statement*>* statements) OVERRIDE;
+  void VisitDeclarations(ZoneList<Declaration*>* declarations) override;
+  void VisitStatements(ZoneList<Statement*>* statements) override;
 
-#define DECLARE_VISIT(type) virtual void Visit##type(type* node) OVERRIDE;
+#define DECLARE_VISIT(type) virtual void Visit##type(type* node) override;
   AST_NODE_LIST(DECLARE_VISIT)
 #undef DECLARE_VISIT