harmony-scoping: Allow 'const' iteration variables in strict mode.

src/preparser.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_PREPARSER_H
 #define V8_PREPARSER_H
 
 #include "src/v8.h"
 
 #include "src/bailout-reason.h"
@@ skipping 326 matching lines @@
   bool peek_any_identifier() {
     Token::Value next = peek();
     return next == Token::IDENTIFIER ||
         next == Token::FUTURE_RESERVED_WORD ||
         next == Token::FUTURE_STRICT_RESERVED_WORD ||
         next == Token::LET ||
         next == Token::YIELD;
   }
 
   bool CheckContextualKeyword(Vector<const char> keyword) {
-    if (peek() == Token::IDENTIFIER &&
-        scanner()->is_next_contextual_keyword(keyword)) {
+    if (PeekContextualKeyword(keyword)) {
       Consume(Token::IDENTIFIER);
       return true;
     }
     return false;
   }
 
+  bool PeekContextualKeyword(Vector<const char> keyword) {
+    return peek() == Token::IDENTIFIER &&
+           scanner()->is_next_contextual_keyword(keyword);
+  }
+
   void ExpectContextualKeyword(Vector<const char> keyword, bool* ok) {
     Expect(Token::IDENTIFIER, ok);
     if (!*ok) return;
     if (!scanner()->is_literal_contextual_keyword(keyword)) {
       ReportUnexpectedToken(scanner()->current_token());
       *ok = false;
     }
   }
 
   // Checks whether an octal literal was last seen between beg_pos and end_pos.
@@ skipping 2462 matching lines @@
       DCHECK(IsAccessorAccessorConflict(old_type, type));
       // Both accessors of the same type.
       parser()->ReportMessage("accessor_get_set");
     }
     *ok = false;
   }
 }
 } }  // v8::internal
 
 #endif  // V8_PREPARSER_H