[date] Add ICU backend for timezone info behind a flag

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 236 matching lines @@
   DEFINE_IMPLICATION(harmony, id)
 HARMONY_STAGED(FLAG_STAGED_FEATURES)
 #undef FLAG_STAGED_FEATURES
 
 #define FLAG_SHIPPING_FEATURES(id, description) \
   DEFINE_BOOL(id, true, "enable " #description) \
   DEFINE_NEG_NEG_IMPLICATION(harmony_shipping, id)
 HARMONY_SHIPPING(FLAG_SHIPPING_FEATURES)
 #undef FLAG_SHIPPING_FEATURES
 
+#ifdef V8_I18N_SUPPORT
+DEFINE_BOOL(icu_timezone_data, false,
+            "get information about timezones from ICU")
+#endif
+
 #ifdef V8_ENABLE_FUTURE
 #define FUTURE_BOOL true
 #else
 #define FUTURE_BOOL false
 #endif
 DEFINE_BOOL(future, FUTURE_BOOL,
             "Implies all staged features that we want to ship in the "
             "not-too-far future")
 DEFINE_IMPLICATION(future, turbo)
 
@@ skipping 1071 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