[modules] Add tests for the name property of default-exported functions.

test/mjsunit/modules-skip-default-name2.js

Index: test/mjsunit/modules-skip-default-name2.js
diff --git a/test/message/regress/regress-4829-1.js b/test/mjsunit/modules-skip-default-name2.js
similarity index 82%
copy from test/message/regress/regress-4829-1.js
copy to test/mjsunit/modules-skip-default-name2.js
index 1ad5feda8cb96cd24e4c47f7407c9699d150c327..a064b0526dff7f964fdba708857c0bc42bbf3033 100644
--- a/test/message/regress/regress-4829-1.js
+++ b/test/mjsunit/modules-skip-default-name2.js
@@ -2,6 +2,4 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-function tag() {}
-
-tag(tag`\xyy`);
+export default (function gaga() {})