Restructure outline shaker tests.

pkg/front_end/testcases/shaker/lib/targets_top.dart

Index: pkg/front_end/testcases/shaker/lib/targets_top.dart
diff --git a/pkg/front_end/testcases/shaker/lib/targets_top.dart b/pkg/front_end/testcases/shaker/lib/targets_top.dart
new file mode 100644
index 0000000000000000000000000000000000000000..0c4c70ef7bc690ce7e891d7b269acb7131fb9e89
--- /dev/null
+++ b/pkg/front_end/testcases/shaker/lib/targets_top.dart
@@ -0,0 +1,11 @@
+// Copyright (c) 2017, 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.
+
+class MyClass {}
+
+typedef void MyFunctionTypeAlias();
+
+int myTopLevelVariable = 0;
+
+int myTopLevelFunction() => 0;