Implement support for specifying string interopolation style variable substitution in the import ...

tests/vm/src/mysrc/test2.dart

Index: tests/vm/src/mysrc/test2.dart
===================================================================
--- tests/vm/src/mysrc/test2.dart	(revision 0)
+++ tests/vm/src/mysrc/test2.dart	(revision 0)
@@ -0,0 +1,13 @@
+// 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('test2.dart');
+
+#source('../$SRC/test2a.dart');
+
+int test2() {
+  var result = test2a();
+  Expect.equals(2, result);
+  return result;
+}