add MutexGuiEnter/Leave to wxAppTraits, integrate native GTK+ GUI locking

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@50757 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/msw/thread.cpp

@@ -1292,7 +1292,7 @@ void wxThreadModule::OnExit()
 // not a mutex, so the names are a bit confusing
 // ----------------------------------------------------------------------------
 
-void WXDLLIMPEXP_BASE wxMutexGuiEnter()
+void wxMutexGuiEnterImpl()
 {
     // this would dead lock everything...
     wxASSERT_MSG( !wxThread::IsMain(),
@@ -1314,7 +1314,7 @@ void WXDLLIMPEXP_BASE wxMutexGuiEnter()
     gs_critsectGui->Enter();
 }
 
-void WXDLLIMPEXP_BASE wxMutexGuiLeave()
+void wxMutexGuiLeaveImpl()
 {
     wxCriticalSectionLocker enter(*gs_critsectWaitingForGui);