Disable kernel unit tests.

pkg/kernel/test/type_unification_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.
 import 'package:kernel/type_algebra.dart';
 import 'package:test/test.dart';
 import 'type_parser.dart';
 import 'dart:io';
 
 final List<TestCase> testCases = <TestCase>[
   successCase('List<T>', 'List<String>', {'T': 'String'}),
@@ skipping 118 matching lines @@
         if (substitution != null) {
           reportFailure(testCase, 'Unification was supposed to fail');
         }
       }
     });
   }
   if (numFailures > 0) {
     exit(1);
   }
 }