[WK2] Run toString & valueOf LayoutTests for WebKit2 also
https://bugs.webkit.org/show_bug.cgi?id=114433

Patch by Arunprasad Rajkumar <arunprasadr@nds.com> on 2013-04-11
Reviewed by Anders Carlsson.

* platform/wk2/TestExpectations:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@148213 268f45cc-cd09-0410-ab3c-d52691b4dbfc