Optimization passes on libqboy

[Eeems]

The CPU utilization for running this is near 100% on a rM1, so it may be worth looking to see if there is any low-hanging fruit for quick optimizations in libqboy. Maybe @calc84maniac would have some insight, since he's written several gameboy emulators on much more limited platforms.

[calc84maniac]

Frankly there's a lot that stands out, I mean I could help optimize it but I'm going to hate every bit of code I look at here 😅

[Eeems]

i.e. gbgpu::preprocessram() and gbgpu::postprocessram() should be replaced by interfaces to the memory mapped registers that just keep themselves up to date as part of the main cpu cycle.