A lot of test ROMs i'm using don't bother to calculate the checksum :\
Former-commit-id: da02a70271c34bc26e560ea18b3f5052ee171a65
Former-commit-id: 332d917e47b268ae649574844d14cab2da65197d
This breaks the API of GameBoyAdvanvce::save_state and restore_state methods.
Currently as WIP only SDL2 frontend will adjust.
Former-commit-id: 1df15c8697fef0f6adddb07a6d653947c622ba12
Former-commit-id: 2ea339dc6a0d1e7539d167c4df29694b408303da
The `if let Some(gpio) = &self.gpio` causes a memory read of `self.gpio` for every Bus::read/write_16.
It is better to reverse the order since `is_gpio_access` does not generate and memory reads and thus less costly.
Former-commit-id: bcce7d9c3a2b159a7f6b291d7b08ccf9c4d0db14
Former-commit-id: 69c12db503c9e612faa7cd8a57f6d862694c8370
