host_syscalls.c: I've written, so put Netflix copyright on. It's
possible in the confusion that Nathan wrote the host_gettimeofday
implementation.
syscall_nr: These files likely can't enjoy copyright protection since
they are just facts (the per-arch Linux system calls), so add a note
they are in the public domain.
Sponsored by: Netflix
For aarch64 and amd64, we don't pull in anything from libkern, so we
don't need it in our path. However, powerpc needs ucmpdi2 from libkern,
so bring it into libkboot's build and omit it from loader.kboot.
Sponsored by: Netflix
Move the startup code from kboot/kboot to kboot/libkboot and add the
necessary infrastructure for it to build. move start_arch.h, a private
header for libkboot, over as well.
Sponsored by: Netflix
