Deallocate wxThreadSpecificInfo when wxThread ends.

Cleanup wxThreadSpecificInfo after wxThread::Entry returns to be more
memory efficient.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74834 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/thread.h

@@ -614,6 +614,8 @@ protected:
     // of this thread.
     virtual void *Entry() = 0;
 
+    // use this to call the Entry() virtual method
+    void *CallEntry();
 
     // Callbacks which may be overridden by the derived class to perform some
     // specific actions when the thread is deleted or killed. By default they