Add parser support for generators.

src/parser.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 690 matching lines @@
     }
     if (StackLimitCheck(isolate()).HasOverflowed()) {
       // Any further calls to Next or peek will return the illegal token.
       // The current call must return the next token, which might already
       // have been peek'ed.
       stack_overflow_ = true;
     }
     return scanner().Next();
   }
 
+  bool inside_generator() const { return top_scope_->inside_generator(); }
+
   bool peek_any_identifier();
 
   INLINE(void Consume(Token::Value token));
   void Expect(Token::Value token, bool* ok);
   bool Check(Token::Value token);
   void ExpectSemicolon(bool* ok);
   void ExpectContextualKeyword(const char* keyword, bool* ok);
 
   Handle<String> LiteralString(PretenureFlag tenured) {
     if (scanner().is_literal_ascii()) {
@@ skipping 156 matching lines @@
  private:
   static const int kTypeSlot = 0;
   static const int kElementsSlot = 1;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(CompileTimeValue);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_PARSER_H_