[es6] support rest parameters in arrow functions (alternative)

src/preparser.cc

 // Copyright 2011 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.
 
 #include <cmath>
 
 #include "src/allocation.h"
 #include "src/base/logging.h"
 #include "src/conversions-inl.h"
 #include "src/conversions.h"
@@ skipping 970 matching lines @@
 
   Scope* scope = NewScope(scope_, BLOCK_SCOPE);
   BlockState block_state(&scope_, scope);
   scope_->SetLanguageMode(
       static_cast<LanguageMode>(scope_->language_mode() | STRICT_BIT));
   // TODO(marja): Make PreParser use scope names too.
   // scope_->SetScopeName(name);
 
   bool has_extends = Check(Token::EXTENDS);
   if (has_extends) {
-    ParseLeftHandSideExpression(CHECK_OK);
+    const bool maybeArrow = false;
+    ParseLeftHandSideExpression(maybeArrow, CHECK_OK);
   }
 
   ClassLiteralChecker checker(this);
   bool has_seen_constructor = false;
 
   Expect(Token::LBRACE, CHECK_OK);
   while (peek() != Token::RBRACE) {
     if (Check(Token::SEMICOLON)) continue;
     const bool in_class = true;
     const bool is_static = false;
@@ skipping 21 matching lines @@
   ParseIdentifier(kAllowEvalOrArguments, CHECK_OK);
   ParseArguments(ok);
 
   return Expression::Default();
 }
 
 #undef CHECK_OK
 
 
 } }  // v8::internal