Revert "Make Comparable generic."

sdk/lib/core/date_time.dart

 // Copyright (c) 2011, 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.
 
 part of dart.core;
 
 /**
  * Deprecated class. Please use [DateTime] instead.
  */
 @deprecated
-abstract class Date implements Comparable<Date> {
+abstract class Date implements Comparable {
   // Weekday constants that are returned by [weekday] method:
   static const int MON = 1;
   static const int TUE = 2;
   static const int WED = 3;
   static const int THU = 4;
   static const int FRI = 5;
   static const int SAT = 6;
   static const int SUN = 7;
   static const int DAYS_IN_WEEK = 7;
 
@@ skipping 485 matching lines @@
    * Returns the millisecond into the second [0...999].
    */
   external int get millisecond;
 
   /**
    * Returns the week day [MON..SUN]. In accordance with ISO 8601
    * a week starts with Monday which has the value 1.
    */
   external int get weekday;
 }