Type test tests for js interop

tests/html/js_type_test_js.js

Index: tests/html/js_type_test_js.js
diff --git a/tests/compiler/dart2js_extra/deferred_custom_loader_lib.dart b/tests/html/js_type_test_js.js
similarity index 92%
copy from tests/compiler/dart2js_extra/deferred_custom_loader_lib.dart
copy to tests/html/js_type_test_js.js
index e8636078fd29a22beb9a84b16232df299e6f114d..1f12f38ea0c64c22aa929bc33a976c51a80208ea 100644
--- a/tests/compiler/dart2js_extra/deferred_custom_loader_lib.dart
+++ b/tests/html/js_type_test_js.js
@@ -2,4 +2,4 @@
 // 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.
 
-foo() => 499;
+function Foo() {}