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

test/cctest/test-parsing.cc

 // 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 6461 matching lines @@
                                    {"function f(argument1, ", ") {}"},
                                    {"var f = (", ") => {};"},
                                    {"var f = (argument1,", ") => {};"},
                                    {NULL, NULL}};
 
   // clang-format off
   const char* data[] = {
     "a",
     "{ x : y }",
     "{ x : y = 1 }",
+    "{ get, set }",
+    "{ get = 1, set = 2 }",
     "[a]",
     "[a = 1]",
     "[a,b,c]",
     "[a, b = 42, c]",
     "{ x : x, y : y }",
     "{ x : x = 1, y : y }",
     "{ x : x, y : y = 42 }",
     "[]",
     "{}",
     "[{x:x, y:y}, [a,b,c]]",
@@ skipping 675 matching lines @@
     "for (let in {}) {}",
     NULL
   };
   // clang-format on
 
   static const ParserFlag always_flags[] = {kAllowHarmonySloppy,
                                             kAllowHarmonySloppyLet};
   RunParserSyncTest(context_data, data, kSuccess, NULL, 0, always_flags,
                     arraysize(always_flags));
 }