Fix dartc bounds checking for invoking interface constructors/factory methods

tests/language/src/DefaultFactory2Test.dart

+// Copyright (c) 2011, 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.
+
+// Check type bounds when invoking a factory method
+
+interface Foo {}
+
+interface IA<T> default A<T extends Foo> { IA(); }

[zundel, 2012/01/04 18:18:19]

Here is the tighter bound.

When you invoke IA<T>, it is really invoking A<T extends Foo>
The constructor must be parameterized with a bound for T that extends Foo.  That
is why there is a static type error at line 16.

+
+class A<T extends Foo> implements IA<T> {
+   factory A(){}
+}
+ 
+main() {
+  var result = new IA<String>();  /// 01: static type error
+}