Improve i18n date/time test performance

pkg/i18n/test/date_time_format_test.dart

 /**
  * Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
  * for details. All rights reserved. Use of this source code is governed by a
  * BSD-style license that can be found in the LICENSE file.
  */
 
 #library('date_time_format_test');
 
 #import('../intl.dart');
 #import('../date_format.dart');
@@ skipping 140 matching lines @@
       DateFormat.ABBR_WEEKDAY,
       DateFormat.WEEKDAY,
       DateFormat.QUARTER,
       DateFormat.ABBR_QUARTER,
       DateFormat.YEAR,
       DateFormat.YEAR_NUM_MONTH,
       DateFormat.YEAR_ABBR_MONTH,
       DateFormat.YEAR_MONTH];
   for(int i = 0; i < formatsToTest.length; i++) {
     var skeleton = formatsToTest[i];
-    var format = new DateFormat(skeleton, localeName);
-    var badPatterns = badSkeletons.map(
-        (x) => new DateFormat(x, format.locale).pattern);
-
-    if (!badPatterns.some((x) => x == format.pattern)) {
+    if (!badSkeletons.some((x) => x == skeleton)) {
+      var format = new DateFormat(skeleton, localeName);
       var actualResult = format.format(date);
       var parsed = format.parse(actualResult);
       var thenPrintAgain = format.format(parsed);
       expect(thenPrintAgain, equals(actualResult));
     }
   }
 }
 
 main() {
   test('Basic date format parsing', () {
-    var date_format = new DateFormat();
+    var date_format = new DateFormat("d");
     expect(
         date_format.parsePattern("hh:mm:ss").map((x) => x.pattern),
         orderedEquals(["hh",":", "mm",":","ss"]));
     expect(
         date_format.parsePattern("hh:mm:ss").map((x) => x.pattern),
         orderedEquals(["hh",":", "mm",":","ss"]));
   });
 
   test('Test ALL the supported formats on representative locales', () {
     var aDate = new Date(2012, 1, 27, 20, 58, 59, 0, false);
@@ skipping 101 matching lines @@
     var localPrinted = format.format(local);
     var parsed = format.parse(localPrinted);
     var parsedUTC = format.parseUTC(format.format(utc));
     var parsedOffset = parsedUTC.millisecondsSinceEpoch
         - parsed.millisecondsSinceEpoch;
     expect(parsedOffset, equals(offset));
     expect(utc.hour, equals(parsedUTC.hour));
     expect(local.hour, equals(parsed.hour));
     });
 }