Port widescreen/HD Mode 7 hack from bsnes-hd

[Margen67]

I'm not sure how difficult it would be to add, but it would be quite nice.
Widescreen works for both Mode 7 and sprite-based games:
https://www.reddit.com/r/emulation/comments/bmc9t9/bsneshd_beta_5_bsnes_1073_formally_hd_mode_7_mod/
Video demonstration: https://youtu.be/RFCWAQlb7y0

[hizzlekizzle]

HD mode 7 isn't going to be easy/plausible because it requires caching the scanlines, which only new bsnes' multithreaded renderer does. I'm not sure if widescreen requires this, as well, but if not, it might be doable.