Track the origin element of inlined arguments to super constructor.

dart/tests/language/inline_super_test.dart

+// 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.
+
+// Regression test for dart2js issue 6639.
+
+library inline_super_test;
+
+part 'inline_super_part.dart';
+
+// Long comment to ensure source positions in the following code are
+// larger than the part file.  Best way to ensure that is to include
+// the part as a comment:
+//
+// class Player extends LivingActor {
+//   Player (deathCallback) : super(null, deathCallback);
+// }
+
+class Percept {}
+
+class Actor {
+  final percept;
+  Actor(this.percept);
+}
+
+class LivingActor extends Actor {
+  // The bug occurs when inlining the node [:new Percept():] into
+  // [Actor]'s constructor.  When this inlining is being initiated
+  // from [Player], we must take care to ensure that we know that we
+  // are inlining from this location, and not [Player].
+  LivingActor () : super(new Percept());
+}
+
+main() {
+  Expect.isTrue(new Player().percept is Percept);
+}