build fixes for wxUSE_THREADS==0

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@58979 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/window.h

@@ -832,7 +832,9 @@ protected:
     //       The same holds for all other wxEvtHandler functions.
 
     using wxEvtHandler::ProcessEvent;
+#if wxUSE_THREADS
     using wxEvtHandler::ProcessThreadEvent;
+#endif
     using wxEvtHandler::SafelyProcessEvent;
     using wxEvtHandler::ProcessPendingEvents;
     using wxEvtHandler::AddPendingEvent;