Make pub's binstubs resilient to changes in snapshot format.

sdk/lib/_internal/pub/test/global/binstubs/name_collision_test.dart

 // Copyright (c) 2014, 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:scheduled_test/scheduled_stream.dart';
 import 'package:scheduled_test/scheduled_test.dart';
 
 import '../../descriptor.dart' as d;
 import '../../test_pub.dart';
-import 'utils.dart';
 
 main() {
   initConfig();
   integration("does not overwrite an existing binstub", () {
     d.dir("foo", [
       d.pubspec({
         "name": "foo",
         "executables": {
           "foo": "foo",
           "collide1": "foo",
@@ skipping 32 matching lines @@
     d.dir(cachePath, [
       d.dir("bin", [
         d.matcherFile(binStubName("foo"), contains("foo:foo")),
         d.matcherFile(binStubName("bar"), contains("bar:bar")),
         d.matcherFile(binStubName("collide1"), contains("foo:foo")),
         d.matcherFile(binStubName("collide2"), contains("foo:foo"))
       ])
     ]).validate();
   });
 }