Migrate test block 3 to Dart 2.0.

tests/corelib_2/compare_to2_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.
 
 import "package:expect/expect.dart";
 
 negate(x) => -x;
 
 main() {
@@ skipping 56 matching lines @@
   check(left, right, expectedResult) {
     if (left is List) {
       for (var x in left) check(x, right, expectedResult);
       return;
     }
     if (right is List) {
       for (var x in right) check(left, x, expectedResult);
       return;
     }
     int actual = left.compareTo(right);
+    print("left: ${left} right: ${right}");

[Bob Nystrom, 2017/07/18 23:43:44]

Remove this.

[bkonyi, 2017/07/19 15:06:21]

Whoops, forgot about this... Done.

     Expect.equals(
         expectedResult,
         actual,
         "($left).compareTo($right) failed "
         "(should have been $expectedResult, was $actual");
   }
 
   for (int i = 0; i < matrix.length; i++) {
     for (int j = 0; j < matrix.length; j++) {
       var left = matrix[i];
       var right = matrix[j];
       if (left is List) {
         check(left, left, 0);
       }
       check(left, right, i == j ? 0 : (i < j ? -1 : 1));
     }
   }
 }