Fix warnings in library-tests.

tests/lib/math/min_max_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.
 // Dart test for testing Math.min and Math.max.
 // VMOptions=--optimization-counter-threshold=10
 
 library min_max_test;
 import "package:expect/expect.dart";
 import 'dart:math';
 
 var inf = double.INFINITY;
 var nan = double.NAN;
 
 // A class that might work if [min] and [max] worked for non-numbers.
 class Wrap implements Comparable {
   final value;
   Wrap(this.value);
-  int compare(Wrap other) => value.compare(other.value);
-  bool operator<(Wrap other) => compare(other) < 0;
-  bool operator<=(Wrap other) => compare(other) <= 0;
-  bool operator>(Wrap other) => compare(other) > 0;
-  bool operator>=(Wrap other) => compare(other) >= 0;
-  bool operator==(other) => other is Wrap && compare(other) == 0;
+  int compareTo(Wrap other) => value.compareTo(other.value);
+  bool operator<(Wrap other) => compareTo(other) < 0;
+  bool operator<=(Wrap other) => compareTo(other) <= 0;
+  bool operator>(Wrap other) => compareTo(other) > 0;
+  bool operator>=(Wrap other) => compareTo(other) >= 0;
+  bool operator==(other) => other is Wrap && compareTo(other) == 0;
   String toString() => 'Wrap($value)';
   int get hashCode => value.hashCode;
 }
 
 var wrap1 = new Wrap(1);
 var wrap2 = new Wrap(2);
 
 testMin() {
   testMin1();
   testMin2();
@@ skipping 537 matching lines @@
   Expect.throws(() => min(wrap1, 0));
   Expect.throws(() => min(0, wrap2));
 }
 
 main() {
   testMin();
   testMin();
   testMax();
   testMax();
 }