fixes #27385, implement virtual fields in DDC

tests/language_strong/abstract_getter2_test.dart

Index: tests/language_strong/abstract_getter2_test.dart
diff --git a/tests/language_strong/abstract_getter2_test.dart b/tests/language_strong/abstract_getter2_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..9553ba4987958ad6aaaede9820203f477fe832a9
--- /dev/null
+++ b/tests/language_strong/abstract_getter2_test.dart
@@ -0,0 +1,27 @@
+// Copyright (c) 2016, 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 "package:expect/expect.dart";
+
+class A {
+  int get x => 100;
+}
+
+abstract class B extends A {
+  int _x;
+
+  int get x;
+  set x(int v) { _x = v; }
+}
+
+class C extends B {
+  int get x => super.x;
+}
+
+void main() {
+  B b = new C();
+  b.x = 42;
+  Expect.equals(b._x, 42);
+  Expect.equals(b.x, 100);
+}