Add test for static methods and named constructors on hidden native class.

tests/language/src/NativeNamedConstructors2FrogTest.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.
+
+// Hidden native class wwith named constructors and static methods.
+
+
+class A native "*A" {
+
+  factory A(int len) => _construct(len);
+
+  factory A.fromString(String s)  => _construct(s.length);
+
+  factory A.nativeConstructor(int a, int b) native @'return makeA(a+b);';
+
+  static A _construct(v) { return makeA(v); }
+
+  foo() native 'return this._x;';
+}
+
+makeA(v) native;
+
+void setup() native """
+// This code is all inside 'setup' and so not accesible from the global scope.
+function A(arg) { this._x = arg; }
+makeA = function(arg) { return new A(arg); }
+""";
+
+main() {
+  setup();
+  var a1 = new A(100);
+  var a2 = new A.fromString('Hello');
+  var a3 = new A.nativeConstructor(100, 2);
+
+  Expect.equals(100, a1.foo());
+  Expect.equals(5, a2.foo());
+  Expect.equals(102, a3.foo());
+}