bug#21333: 25.0.50; window-size-change-functions not called after mini-window resize

[martin rudalics]

> The call order is that redisplay_internal calls prepare_menu_bars, then
> calls grow_mini_window, then performs the frame update. It doesn't go back
> to calling prepare_menu_bars, ...

But this also means that your initial patch wouldn't help anyway.  Even
if we set WINDOW_SIZES_CHANGED in grow_/shrink_mini_window,
‘window-size-change-functions’ won't be called any more in the present
cycle.

martin