Disable kernel unit tests.

pkg/kernel/test/type_substitute_bounds_test_disabled.dart

 // Copyright (c) 2016, 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.
 library kernel.type_substitute_bounds_test;
 
 import 'package:kernel/kernel.dart';
 import 'package:kernel/type_algebra.dart';
 import 'package:test/test.dart';
 import 'type_parser.dart';
 
@@ skipping 64 matching lines @@
       var substituted = Substitution
           .fromUpperAndLowerBounds(upperBounds, lowerBounds)
           .substituteType(type);
       var expected = environment.parse(testCase.expected);
       if (substituted != expected) {
         fail('Expected `$expected` but got `$substituted`');
       }
     });
   }
 }