Add mirrors tests

test/codegen/lib/mirrors/library_uri_io_test.dart

+// Copyright (c) 2013, 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.
+
+// Test library uri for a library read as a file.
+
+library MirrorsTest;
+
+import 'dart:mirrors';
+import 'dart:io';
+import 'package:unittest/unittest.dart';
+
+class Class {
+}
+
+testLibraryUri(var value, Uri expectedUri) {
+  var valueMirror = reflect(value);
+  ClassMirror valueClass = valueMirror.type;
+  LibraryMirror valueLibrary = valueClass.owner;
+  expect(valueLibrary.uri, equals(expectedUri));
+}
+
+main() {
+  var mirrors = currentMirrorSystem();
+  test("Test current library uri", () {
+    Uri uri = Uri.base.resolveUri(Platform.script);
+    testLibraryUri(new Class(), uri);
+  });
+}