vkCreateDevice may fail

[Megamouse]

It's hard to reproduce, but sometimes RPCS3 triggers a breakpoint in vkCreateDevice.
It may also get stuck without any error on that exact line.

You may reproduce it by constantly starting and stopping a game:
Step 1: choose a simple game that doesn't take long to boot.
Step 2: press play button in RPCS3 main window
Step 3: wait until the game window opened
Step 4: press stop button in RPCS3 main window
Step 5: repeat steps 2-4 until you get either stuck or it triggers the breakpoint (this may take some time)

[kd-11]

This should happen if you destroy the window in one thread and create a device in another. There is no way to tell the OS to hold my window handle for me so the only option I suppose is to block the game window destructor until a context has been created. However, I can already see many ways in which this can fail.
Note that because on some platforms Qt never actually registers the window with the windowing subsystem until it is visible, hiding the window is not really an option here. Alternatively, the windowing can be done by the backend but that defeats the purpose of having Qt. I'll think of some easier workaround later.

[Megamouse]

I can't really reproduce this after #10430.
So I'll close this for now