Made dart2js constructor lookup logic "private"-aware, fixed 4740 bug.

tests/compiler/dart2js_extra/regress/4740_test.dart

Index: tests/compiler/dart2js_extra/regress/4740_test.dart
diff --git a/tests/compiler/dart2js_extra/regress/4740_test.dart b/tests/compiler/dart2js_extra/regress/4740_test.dart
deleted file mode 100644
index e2df2c35ca04cb39583671505d1c66aa0b517a2e..0000000000000000000000000000000000000000
--- a/tests/compiler/dart2js_extra/regress/4740_test.dart
+++ /dev/null
@@ -1,9 +0,0 @@
-// 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.
-
-#import('4740_library.dart');
-
-main() {
-  Expect.throws(() => new Foo._internal(), (e) => e is NoSuchMethodError);
-}