Upper screen flickering (0.7b1)

[pseiler]

First of all the 0.7 beta is really nice! Now I get stable 60 fps on a pokemon romhack which wasn't possible on the 3ds before.

But when starting the emulator, the upper screen flickers. Also when I load a rom and change the output to the bottom screen, the last frame before changing is still present on the upper screen. This can only be fixed when changing the output to the upper screen again.

I think something broke regarding the handling of two screens.

Screen flickering:
https://www.youtube.com/watch?v=7cBhKVGTGKk

upper screen freeze:
https://abload.de/img/img_20180927_200250h1eij.jpg

My device is a New 3DS.
When my Vita is repaired again I will also test the Vita port.

[endrift]

Dupe of #1184. It's been fixed already.