because it was mostly irrelevant - except for the silly BIOS_PADDRTOVADDR
etc macros. Along the way of working around this, I missed a few things.
* Make syscons properly inherit the bios capslock/shiftlock/etc state like
i386 does. Note that we cannot inherit the bios key repeat rate because
that requires a bios call (which is impossible for us).
* Give syscons the ability to beep on amd64. Oops.
While here, make bios.c compile and add it to files.amd64.