Change getRange to sublist. Make getRange deprecated.

pkg/intl/lib/src/date_format_helpers.dart

Index: pkg/intl/lib/src/date_format_helpers.dart
diff --git a/pkg/intl/lib/src/date_format_helpers.dart b/pkg/intl/lib/src/date_format_helpers.dart
index a10b27462c71eb46b378e6af587da0623f967fee..253a4e61f2dc31824aa1781e3fdd77e3ae114d67 100644
--- a/pkg/intl/lib/src/date_format_helpers.dart
+++ b/pkg/intl/lib/src/date_format_helpers.dart
@@ -98,7 +98,7 @@ class _Stream {
           min(index + howMany, contents.length));
     } else {
       // Assume List
-      result = contents.getRange(index, howMany);
+      result = contents.sublist(index, index + howMany);
     }
     return result;
   }