Flipped sprites are clipped incorrectly when going offscreen
Sprites with BLIT_FLIP_X flag clip incorrectly when going offscreen to the right

Here is my C code, one with a normal sprite, and another flipped.
`blit(witch2, player.x, player.y,      witch2Width, witch2Height, BLIT_2BPP);`
`blit(witch2, player.x, player.y + 20, witch2Width, witch2Height, BLIT_2BPP | BLIT_FLIP_X);`

It only happens when going offscreen to the right.

Attaching gif of the same sprites, one flipped
![game2](https://user-images.githubusercontent.com/10901731/150590802-bad5f3e6-226a-4a21-9e1a-0c4520b4ccf5.gif)