Add support for importing using "package:" to the standalone VM.

tests/standalone/src/package/InvalidUriTest.dart

Index: tests/standalone/src/package/InvalidUriTest.dart
diff --git a/tests/standalone/src/package/InvalidUriTest.dart b/tests/standalone/src/package/InvalidUriTest.dart
new file mode 100644
index 0000000000000000000000000000000000000000..766dc7690236d0cff3cec76ae9521c2352793cf9
--- /dev/null
+++ b/tests/standalone/src/package/InvalidUriTest.dart
@@ -0,0 +1,10 @@
+// Copyright (c) 2012, 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.
+
+#library('invalid_uri_test');
+
+#import('package://lib1.dart'); // Should not contain "//".
+
+void main() {
+}