tzname check fix

test/mjsunit/regress/regress-crbug-487322.js

+// Copyright 2015 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.
+
+if (this.Intl) {
+  // Normalizes Kat{h,}mandu (chromium:487322)
+  // According to the IANA timezone db, Kathmandu is the current canonical
+  // name, but ICU got it backward. To make this test robust against a future
+  // ICU change ( http://bugs.icu-project.org/trac/ticket/12044 ),
+  // just check that Kat(h)mandu is resolved identically.
+  df1 = new Intl.DateTimeFormat('en-US', {'timeZone': 'Asia/Katmandu'})
+  df2 = new Intl.DateTimeFormat('en-US', {'timeZone': 'Asia/Kathmandu'})
+  assertEquals(df1.resolvedOptions().timeZone, df2.resolvedOptions().timeZone);
+
+  // Normalizes Ulan_Bator to Ulaanbaatar. Unlike Kat(h)mandu, ICU got this
+  // right so that we make sure that Ulan_Bator is resolved to Ulaanbaatar.
+  df = new Intl.DateTimeFormat('en-US', {'timeZone': 'Asia/Ulaanbaatar'})
+  assertEquals('Asia/Ulaanbaatar', df.resolvedOptions().timeZone);
+
+  df = new Intl.DateTimeFormat('en-US', {'timeZone': 'Asia/Ulan_Bator'})
+  assertEquals('Asia/Ulaanbaatar', df.resolvedOptions().timeZone);
+
+  // Throws for unsupported time zones.
+  assertThrows(() => Intl.DateTimeFormat(undefined, {timeZone: 'Aurope/Paris'}));
+}