Add new test configuration fields.

lib/src/backend/platform_selector.dart

 // Copyright (c) 2015, 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:boolean_selector/boolean_selector.dart';
 import 'package:source_span/source_span.dart';
 
 import 'operating_system.dart';
 import 'test_platform.dart';
 
@@ skipping 48 matching lines @@
   }
 
   /// Returns a new [PlatformSelector] that matches only platforms matched by
   /// both [this] and [other].
   PlatformSelector intersection(PlatformSelector other) {
     if (other == PlatformSelector.all) return this;
     return new PlatformSelector._(_inner.intersection(other._inner));
   }
 
   String toString() => _inner.toString();
+
+  bool operator==(other) => other is PlatformSelector && _inner == other._inner;
+
+  int get hashCode => _inner.hashCode;
 }