Stop using the Hashable interface.

pkg/fixnum/intx.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.
 
 /**
  * A fixed-precision integer.
  */
-abstract class intx implements Comparable, Hashable {
+abstract class intx implements Comparable {
 
   // Arithmetic operations.
   intx operator +(other);
   intx operator -(other);
   // The unary '-' operator.  Note that -MIN_VALUE will be equal
   // to MIN_VALUE due to overflow.
   intx operator -();
   intx operator *(other);
   intx operator %(other);
   // Truncating division.
@@ skipping 75 matching lines @@
    * Returns the value of this [intx] as a hexadecimal [String].
    */
   String toHexString();
 
   /**
    * Returns the value of this [intx] as a [String] in the given radix.
    * [radix] must be an integer between 2 and 16, inclusive.
    */
   String toRadixString(int radix);
 }