Thread static data destructors are not guaranteed to be called in any particular order;
        turn ThreadSpecific into a phoenix-style singleton to avoid accessing freed memory when
        deleted objects are interdependent (e.g. CommonIdentifiers and internal identifier tables).

        No change on SunSpider.

        * wtf/ThreadSpecific.h:
        (WTF::ThreadSpecific::Data::Data):
        (WTF::::get):
        (WTF::::set):
        (WTF::::destroy):



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@32000 268f45cc-cd09-0410-ab3c-d52691b4dbfc