winemac: Clean up fully-delivered events in queues which aren't being drained.

Some events get queued for all GUI-connected threads but are only processed
by the first to dequeue them.  Other threads which tend their event queue
discard such already-processed events.  However, some threads may be
connected to the GUI but never tend their event queue.  To prevent such
threads from accumulating zombie events, the zombies are cleared each time a
new event is queued.

dlls/winemac.drv/cocoa_event.m

@@ -171,10 +171,16 @@ - (void) signalEventAvailable
 
     - (void) postEventObject:(MacDrvEvent*)event
     {
+        NSIndexSet* indexes;
         MacDrvEvent* lastEvent;
 
         [eventsLock lock];
 
+        indexes = [events indexesOfObjectsPassingTest:^BOOL(id obj, NSUInteger idx, BOOL *stop){
+            return ((MacDrvEvent*)obj)->event->deliver <= 0;
+        }];
+        [events removeObjectsAtIndexes:indexes];
+
         if ((event->event->type == MOUSE_MOVED ||
              event->event->type == MOUSE_MOVED_ABSOLUTE) &&
             event->event->deliver == INT_MAX &&