EventLoopWindowTarget::exit() doesn't immediately stop the event loop

[ItsSunnyMonster]

I didn't file this as an issue because I don't know if I missed something or if this is the intended behaviour. When I call EventLoopWindowTarget::exit() in my event loop after all windows have been closed, on Windows, I would receive another bunch of events after that, including another AboutToWait event where I draw a frame. On macOS a NewEvents(WaitCancelled) event still gets emitted but that doesn't affect anything because I don't handle that event yet. Why is this?

[daxpedda]

Moved to #3323.