Enable ES6 Symbols by default

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 135 matching lines @@
 //
 #define FLAG FLAG_FULL
 
 // Flags for language modes and experimental language features.
 DEFINE_BOOL(use_strict, false, "enforce strict mode")
 DEFINE_BOOL(es_staging, false, "enable upcoming ES6+ features")
 
 DEFINE_BOOL(harmony_scoping, false, "enable harmony block scoping")
 DEFINE_BOOL(harmony_modules, false,
             "enable harmony modules (implies block scoping)")
-DEFINE_BOOL(harmony_symbols, false, "enable harmony symbols")
 DEFINE_BOOL(harmony_proxies, false, "enable harmony proxies")
 DEFINE_BOOL(harmony_collections, false,
             "enable harmony collections (sets, maps)")
 DEFINE_BOOL(harmony_generators, false, "enable harmony generators")
 DEFINE_BOOL(harmony_iteration, false, "enable harmony iteration (for-of)")
 DEFINE_BOOL(harmony_numeric_literals, false,
             "enable harmony numeric literals (0o77, 0b11)")
 DEFINE_BOOL(harmony_strings, false, "enable harmony string")
 DEFINE_BOOL(harmony_arrays, false, "enable harmony arrays")
 DEFINE_BOOL(harmony_arrow_functions, false, "enable harmony arrow functions")
 DEFINE_BOOL(harmony, false, "enable all harmony features")
 
 DEFINE_IMPLICATION(harmony, harmony_scoping)
 DEFINE_IMPLICATION(harmony, harmony_modules)
 DEFINE_IMPLICATION(harmony, harmony_proxies)
 DEFINE_IMPLICATION(harmony, harmony_collections)
 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_collections, harmony_symbols)
-DEFINE_IMPLICATION(harmony_generators, harmony_symbols)
-DEFINE_IMPLICATION(harmony_iteration, harmony_symbols)
 
 DEFINE_IMPLICATION(harmony, es_staging)
-DEFINE_IMPLICATION(es_staging, harmony_symbols)
 DEFINE_IMPLICATION(es_staging, harmony_collections)
 DEFINE_IMPLICATION(es_staging, harmony_iteration)
 
 // 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 +")
@@ skipping 719 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