Fix inferrer bug in the presence of synthesized constructors: we should always notify a call to the…

tests/language/inferrer_synthesized_constructor_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.
+
+// Regression test for dart2js's type inferrer that used to not
+// propagate default types in synthesized calls.
+
+import "package:expect/expect.dart";
+
+class A {
+  final x;
+  A([this.x = 'foo']);
+}
+
+class B extends A {
+  // The synthesized constructor was not saying that it would call
+  // [A]'s constructor with its default type.
+}
+
+main() {
+  // By calling [B]'s constructor with an int parameter, the inferrer
+  // used to only see this call and consider the [A.x] field to always
+  // be int.
+  Expect.equals(84, new A(42).x + 42);
+  Expect.throws(() => new B().x + 42, (e) => e is ArgumentError);
+}