Implement "Extend TimeZoneName Option Proposal"

https://tc39.es/proposal-intl-extend-timezonename/
https://chromestatus.com/guide/edit/4506375298220032

Bugs: v8:11661

Change-Id: I6d7e1bccf5a26ca02d39dc72d9362134a60ad6b9
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2757899Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Frank Tang <ftang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74809}

src/flags/flag-definitions.h

@@ -280,7 +280,8 @@ DEFINE_BOOL(harmony_shipping, true, "enable all shipped harmony features")
 #ifdef V8_INTL_SUPPORT
 #define HARMONY_INPROGRESS(V) \
   HARMONY_INPROGRESS_BASE(V)  \
-  V(harmony_intl_displaynames_date_types, "Intl.DisplayNames date types")
+  V(harmony_intl_displaynames_date_types, "Intl.DisplayNames date types") \
+  V(harmony_intl_more_timezone, "More Timezone")
 #else
 #define HARMONY_INPROGRESS(V) HARMONY_INPROGRESS_BASE(V)
 #endif

src/init/bootstrapper.cc

@@ -4434,6 +4434,7 @@ EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_error_cause)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_intl_best_fit_matcher)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_intl_displaynames_date_types)
 EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_intl_dateformat_day_period)
+EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE(harmony_intl_more_timezone)
 #endif  // V8_INTL_SUPPORT
 
 #undef EMPTY_INITIALIZE_GLOBAL_FOR_FEATURE

src/objects/js-date-time-format.cc

@@ -168,8 +168,23 @@ static std::vector<PatternItem> BuildPatternItems() {
                               k2DigitNumeric));
   items.push_back(PatternItem("second", {{"ss", "2-digit"}, {"s", "numeric"}},
                               k2DigitNumeric));
-  items.push_back(PatternItem("timeZoneName",
-                              {{"zzzz", "long"}, {"z", "short"}}, kLongShort));
+
+  if (FLAG_harmony_intl_more_timezone) {
+    const std::vector<const char*> kTimezone = {"long",        "short",
+                                                "longOffset",  "shortOffset",
+                                                "longGeneric", "shortGeneric"};
+    items.push_back(PatternItem("timeZoneName",
+                                {{"zzzz", "long"},
+                                 {"z", "short"},
+                                 {"OOOO", "longOffset"},
+                                 {"O", "shortOffset"},
+                                 {"vvvv", "longGeneric"},
+                                 {"v", "shortGeneric"}},
+                                kTimezone));
+  } else {
+    items.push_back(PatternItem(
+        "timeZoneName", {{"zzzz", "long"}, {"z", "short"}}, kLongShort));
+  }
   return items;
 }
 

test/intl/date-format/timezone-name-extended.js

+// Copyright 2021 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.
+// Flags:  --harmony_intl_more_timezone
+
+// Tests time zone names.
+
+// Winter date (PST).
+var winter = new Date(2013, 1, 12, 14, 42, 53, 0);
+
+// Summer date (PDT).
+var summer = new Date(2013, 7, 12, 14, 42, 53, 0);
+
+// Common flags for both formatters.
+var flags = {
+  year: 'numeric', month: 'long', day: 'numeric',
+  hour : '2-digit', minute : '2-digit', second : '2-digit',
+  timeZone: 'America/Los_Angeles'
+};
+
+flags.timeZoneName = "short";
+var dfs = new Intl.DateTimeFormat('en-US', flags);
+
+assertTrue(dfs.format(winter).indexOf('PST') !== -1);
+assertTrue(dfs.format(summer).indexOf('PDT') !== -1);
+assertEquals(flags.timeZoneName, dfs.resolvedOptions().timeZoneName);
+
+flags.timeZoneName = "long";
+var dfl = new Intl.DateTimeFormat('en-US', flags);
+
+assertTrue(dfl.format(winter).indexOf('Pacific Standard Time') !== -1);
+assertTrue(dfl.format(summer).indexOf('Pacific Daylight Time') !== -1);
+assertEquals(flags.timeZoneName, dfl.resolvedOptions().timeZoneName);
+
+flags.timeZoneName = "shortGeneric";
+var dfsg = new Intl.DateTimeFormat('en-US', flags);
+
+assertTrue(dfsg.format(winter).indexOf('PT') !== -1);
+assertTrue(dfsg.format(summer).indexOf('PT') !== -1);
+assertEquals(flags.timeZoneName, dfsg.resolvedOptions().timeZoneName);
+
+flags.timeZoneName = "longGeneric";
+var dflg = new Intl.DateTimeFormat('en-US', flags);
+
+assertTrue(dflg.format(winter).indexOf('Pacific Time') !== -1);
+assertTrue(dflg.format(summer).indexOf('Pacific Time') !== -1);
+assertEquals(flags.timeZoneName, dflg.resolvedOptions().timeZoneName);
+
+flags.timeZoneName = "shortOffset";
+var dfso = new Intl.DateTimeFormat('en-US', flags);
+
+assertTrue(dfso.format(winter).indexOf('GMT-8') !== -1);
+assertTrue(dfso.format(summer).indexOf('GMT-7') !== -1);
+assertEquals(flags.timeZoneName, dfso.resolvedOptions().timeZoneName);
+
+flags.timeZoneName = "longOffset";
+var dflo = new Intl.DateTimeFormat('en-US', flags);
+
+assertTrue(dflo.format(winter).indexOf('GMT-08:00') !== -1);
+assertTrue(dflo.format(summer).indexOf('GMT-07:00') !== -1);
+assertEquals(flags.timeZoneName, dflo.resolvedOptions().timeZoneName);