[es6] support `get` and `set` in shorthand properties

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/bailout-reason.h"
 #include "src/expression-classifier.h"
 #include "src/func-name-inferrer.h"
@@ skipping 2637 matching lines @@
         CHECK_OK_CUSTOM(EmptyObjectLiteralProperty));
 
     return factory()->NewObjectLiteralProperty(name_expression, value,
                                                ObjectLiteralProperty::COMPUTED,
                                                is_static, *is_computed_name);
 
   } else if (in_class && name_is_static && !is_static) {
     // static MethodDefinition
     return ParsePropertyDefinition(checker, true, has_extends, true,
                                    is_computed_name, nullptr, classifier, ok);
-  } else if (is_get || is_set) {
+  } else if ((is_get || is_set) &&
+             (in_class || (peek() != Token::RBRACE && peek() != Token::COMMA &&
+                           peek() != Token::ASSIGN))) {
     // Accessor
     name = this->EmptyIdentifier();
     bool dont_care = false;
     name_token = peek();
 
     name_expression = ParsePropertyName(
         &name, &dont_care, &dont_care, &dont_care, is_computed_name, classifier,
         CHECK_OK_CUSTOM(EmptyObjectLiteralProperty));
 
     if (!*is_computed_name) {
@@ skipping 1488 matching lines @@
       *ok = false;
       return;
     }
     has_seen_constructor_ = true;
     return;
   }
 }
 } }  // v8::internal
 
 #endif  // V8_PREPARSER_H