Add more tests for .packages

tests/standalone/package/scenarios/invalid/invalid_package_name_test.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.
 
 // PackageRoot=none
+// Packages=invalid_package_name.packages
 
-library packages_file_in_parent_test;
+library invalid_package_name_test;
 
 import 'package:foo/foo.dart' as foo;
 
 main() {
-  if (foo.bar != 'hello') {
+  if (foo.foo != 'foo') {
     throw new Exception('package "foo" was not resolved correctly');
   }
 }