[es6] implement Object.assign

src/flag-definitions.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.
 
 // This file defines all of the flags.  It is separated into different section,
 // for Debug, Release, Logging and Profiling, etc.  To add a new flag, find the
 // correct section, and use one of the DEFINE_ macros, without a trailing ';'.
 //
 // This include does not have a guard, because it is a template-style include,
 // which can be included multiple times in different modes.  It expects to have
@@ skipping 152 matching lines @@
 
 // Features that are still work in progress (behind individual flags).
 #define HARMONY_INPROGRESS(V)                                             \
   V(harmony_modules, "harmony modules (implies block scoping)")           \
   V(harmony_arrays, "harmony array methods")                              \
   V(harmony_regexps, "harmony regular expression extensions")             \
   V(harmony_arrow_functions, "harmony arrow functions")                   \
   V(harmony_proxies, "harmony proxies")                                   \
   V(harmony_templates, "harmony template literals")                       \
   V(harmony_sloppy, "harmony features in sloppy mode")                    \
-  V(harmony_unicode, "harmony unicode escapes")
+  V(harmony_unicode, "harmony unicode escapes")                           \
+  V(harmony_object, "harmony Object methods")
 
 // Features that are complete (but still behind --harmony/es-staging flag).
 #define HARMONY_STAGED(V)                                                 \
   V(harmony_classes,                                                      \
     "harmony classes (implies block scoping & object literal extension)") \
   V(harmony_object_literals, "harmony object literal extensions")         \
   V(harmony_tostring, "harmony toString")                                 \
   V(harmony_scoping, "harmony block scoping")
 
 // Features that are shipping (turned on by default, but internal flag remains).
@@ skipping 808 matching lines @@
 #undef DEFINE_ALIAS_FLOAT
 #undef DEFINE_ALIAS_ARGS
 
 #undef FLAG_MODE_DECLARE
 #undef FLAG_MODE_DEFINE
 #undef FLAG_MODE_DEFINE_DEFAULTS
 #undef FLAG_MODE_META
 #undef FLAG_MODE_DEFINE_IMPLICATIONS
 
 #undef COMMA