Keep generic and CPU/platform-specific code at arms’ length

[eschaton]

Eventually I suspect Mezzano will want to support more CPUs than just x86_64. (For example, ARM; I could see Mezzano running on something like a Raspberry Pi 3.) It would probably be worthwhile to keep the CPU & platform-specific code as separate as possible from the start.

[lehitoskin]

I second this. If the TALOS POWER8 workstation releases, I certainly want to pick that up, but all of the amd64-specific code for Mezzano would need to be ported over before it'd work.