gles2rice: Fix some obvious regressions.

cherry-picked from
https://github.com/libretro/mupen64plus-libretro/commit/89c985f38a2b468ea8b08691f7898ce898aea575
gles2n64: Possible bugfix (see log message).

Fixes totally broken graphics in Diddy Kong Racing, Jet Force Gemini,
Mickey's Speedway Racing - graphics should now be fine.

cherry pick from:
https://github.com/libretro/mupen64plus-libretro/commit/a4352f310def07c183311a4bcf996937d8746aab

littleguy77 said:
   Just to be clear in the git-log -- could you elaborate on what this
   fixes? I've played a fair bit of Diddy but the only broken graphics
   I've ever seen with gles2n64 were that it is missing most of the UI
   at the top of the screen (clock, race position, lap, etc.)... which
   this doesn't address.

twinaphex said:
   The polygons were a total garbled mess before with gln64 - I dunno
   if this was only the case with our libretro fork (related to how we
   push VBO data to the server side) but it was definitely an issue on
   our end. I think I have only seen a user post a bug with

   Anyway - the UI shows up just fine on my end.

   If this doesn't change anything on your end and fixes nothing then
   just ignore I guess - it will be just a libretro quirk I will have
   to do then.