Add FINAL and OVERRIDE macros for C++11 final/override.

src/ast.h

Index: src/ast.h
diff --git a/src/ast.h b/src/ast.h
index a8b74213adb663dce6c0fb3bad9ae8c45ea8a648..8557ac2f45229af70780a6bbce66b1b55a19b256 100644
--- a/src/ast.h
+++ b/src/ast.h
@@ -2144,10 +2144,10 @@ class Yield: public Expression {
   DECLARE_NODE_TYPE(Yield)
 
   enum Kind {
-    INITIAL,     // The initial yield that returns the unboxed generator object.
-    SUSPEND,     // A normal yield: { value: EXPRESSION, done: false }
-    DELEGATING,  // A yield*.
-    FINAL        // A return: { value: EXPRESSION, done: true }
+    kInitial,     // The initial yield that returns the unboxed generator object
+    kSuspend,     // A normal yield: { value: EXPRESSION, done: false }
+    kDelegating,  // A yield*.
+    kFinal        // A return: { value: EXPRESSION, done: true }
   };
 
   Expression* generator_object() const { return generator_object_; }
@@ -2159,11 +2159,11 @@ class Yield: public Expression {
   // locates the catch handler in the handler table, and is equivalent to
   // TryCatchStatement::index().
   int index() const {
-    ASSERT(yield_kind() == DELEGATING);
+    ASSERT(yield_kind() == kDelegating);
     return index_;
   }
   void set_index(int index) {
-    ASSERT(yield_kind() == DELEGATING);
+    ASSERT(yield_kind() == kDelegating);
     index_ = index;
   }