Implement modular compilation

test/samples/import_test.dart

Index: test/samples/import_test.dart
diff --git a/test/samples/import_test.dart b/test/samples/import_test.dart
deleted file mode 100644
index e02c69eade6c5fdd1477fc6a078699c8d127ad7b..0000000000000000000000000000000000000000
--- a/test/samples/import_test.dart
+++ /dev/null
@@ -1,21 +0,0 @@
-// 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.
-
-import 'imported_file.dart';
-
-class B extends A {
-  int b = 0;
-}
-
-test1() {
-  B x = new A();
-  print(x.a);
-  print(x.b);
-}
-
-test2() {
-  A x = new B();
-  print(x.a);
-  print(x.b);
-}