[PATCH] fix libstdc++/52604 : __freelist::~__freelist re-initializes _M_thread_freelist

[Laurent Alfonsi]

Also, here is the Changelog :

2012-04-13  Laurent Alfonsi <laurent.alfonsi@st.com>

         PR libstdc++/52604
         * src/mt_allocator.cc: (__freelist::~__freelist): Reset pointer.