Rework new_dynarec by copying what was done by pcsx-rearmed; it will run games on iOS but crashes frequently
(iOS dynarec) Save extra registers needed for abi compat
(iOS dynarec) Put .bss data in the actual bss sectiom, shaves 36MB off the library file size.
(iOS Dynarec) Fix crash when closing game
Merge branch 'iosdynarec2' of https://github.com/libretro/mupen64plus-libretro