Fix bug in checked mode: we need to register super fields as well, because the super class might no…

tests/language/checked_setter_test.dart

+// Copyright (c) 2013, 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.
+
+// Test that implicit setters in checked mode do a type check.
+
+import "package:expect/expect.dart";
+
+class A {
+  C c;
+}
+
+class B extends A {
+}
+
+class C {
+}
+
+var array = [new B()];
+
+main() {
+  array[0].c = new C();
+  bool inCheckedMode = false;
+  try {
+    String a = 42;
+  } catch (e) {
+    inCheckedMode = true;
+  }
+  if (inCheckedMode) {
+    Expect.throws(() => array[0].c = new B(), (e) => e is TypeError);
+  }
+}