pkg/(unit)test: include a copy of old matcher

lib/src/matcher.dart

Index: lib/src/matcher.dart
diff --git a/lib/src/matcher.dart b/lib/src/matcher.dart
new file mode 100644
index 0000000000000000000000000000000000000000..cfd58573ad15538d86cdee243d76a13702edee29
--- /dev/null
+++ b/lib/src/matcher.dart
@@ -0,0 +1,22 @@
+// 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.
+
+/// Support for specifying test expectations, such as for unit tests.
+library unittest.matcher;
+
+export 'matcher/core_matchers.dart';
+export 'matcher/description.dart';
+export 'matcher/error_matchers.dart';
+export 'matcher/expect.dart';
+export 'matcher/future_matchers.dart';
+export 'matcher/interfaces.dart';
+export 'matcher/iterable_matchers.dart';
+export 'matcher/map_matchers.dart';
+export 'matcher/numeric_matchers.dart';
+export 'matcher/operator_matchers.dart';
+export 'matcher/prints_matcher.dart';
+export 'matcher/string_matchers.dart';
+export 'matcher/throws_matcher.dart';
+export 'matcher/throws_matchers.dart';
+export 'matcher/util.dart';