Update Intl date and number formatting to CLDR 25.

pkg/intl/test/date_time_format_test_core.dart

Index: pkg/intl/test/date_time_format_test_core.dart
diff --git a/pkg/intl/test/date_time_format_test_core.dart b/pkg/intl/test/date_time_format_test_core.dart
index 65104816ad29b08b4265e02d7088975f47676471..6ac9d75af3c24e0f4a556da239785653dc1b3546 100644
--- a/pkg/intl/test/date_time_format_test_core.dart
+++ b/pkg/intl/test/date_time_format_test_core.dart
@@ -248,22 +248,9 @@ void runDateTests(Function subsetFunc) {
     }
   });
 
-  test('Patterns and symbols have the same coverage',() {
-    // Don't run if we have just one locale, so checking coverage isn't
-    // very meaningful.
-    if (subset.length <= 1) return;
-    var patterns = new List.from(dateTimePatterns.keys);
-    var compare = (a, b) => a.compareTo(b);
-    patterns.sort(compare);
-    var symbols = allLocales();
-    // Workaround for a dartj2 issue that treats the keys as immutable
-    symbols = new List.from(symbols);
-    symbols.sort(compare);
-    for (var i = 0; i < patterns.length; i++) {
-      expect(patterns[i], equals(symbols[i]));
-    }
-    expect(patterns.length, equals(symbols.length));
-  });
+  // TODO(alanknight): The coverage for patterns and symbols differs
+  // at the source, in CLDR 25, so we can't guarantee that all patterns
+  // have symbols or vice versa. Wish we could.
 
   test('Test malformed locales', () {
     // Don't run if we have just one locale, which may not include these.