RinHizakura

The new option `--group-bytes` will provide the functionality to group multiple octets as a unit, which means that several bytes will be shown together without whitespace. It is quite similar...

It is basically the same as `-groupsize` in `xxd`. Since I didn't aware of the requirement of compatibility, so the naming didn't align with `xxd` at that time. I think...

For the part of the instruction cache, it can really help a lot for system emulators. In my experience, I have [icache.c](https://github.com/RinHizakura/riscv-emulator/blob/main/src/icache.c) on my risc-v emulator, and it improves performance...