Turn on harmony_unscopables for es_staging

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 156 matching lines @@
 DEFINE_IMPLICATION(harmony, harmony_modules)
 DEFINE_IMPLICATION(harmony, harmony_proxies)
 DEFINE_IMPLICATION(harmony, harmony_generators)
 DEFINE_IMPLICATION(harmony, harmony_numeric_literals)
 DEFINE_IMPLICATION(harmony, harmony_strings)
 DEFINE_IMPLICATION(harmony, harmony_arrays)
 DEFINE_IMPLICATION(harmony, harmony_arrow_functions)
 DEFINE_IMPLICATION(harmony_modules, harmony_scoping)
 
 DEFINE_IMPLICATION(harmony, es_staging)
+DEFINE_IMPLICATION(es_staging, harmony_unscopables)
 
 // Flags for experimental implementation features.
 DEFINE_BOOL(compiled_keyed_dictionary_loads, true,
             "use optimizing compiler to generate keyed dictionary load stubs")
 DEFINE_BOOL(compiled_keyed_generic_loads, false,
             "use optimizing compiler to generate keyed generic load stubs")
 DEFINE_BOOL(clever_optimizations, true,
             "Optimize object size, Array shift, DOM strings and string +")
 // TODO(hpayer): We will remove this flag as soon as we have pretenuring
 // support for specific allocation sites.
@@ skipping 737 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