ES6 symbols: Implement Symbol intrinsic and basic functionality

tools/gyp/v8.gyp

 # 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 769 matching lines @@
               '../../src/debug-debugger.js',
               '../../src/mirror-debugger.js',
               '../../src/liveedit-debugger.js',
               '../../src/date.js',
               '../../src/json.js',
               '../../src/regexp.js',
               '../../src/macros.py',
             ],
             'experimental_library_files': [
               '../../src/macros.py',
+              '../../src/symbol.js',
               '../../src/proxy.js',
               '../../src/collection.js',
               '../../src/object-observe.js'
             ],
           },
           'actions': [
             {
               'action_name': 'js2c',
               'inputs': [
                 '../../tools/js2c.py',
@@ skipping 249 matching lines @@
             }],
           ],
           'dependencies': [
             'v8'
           ],
         },
       ],
     }],
   ],
 }