This is xnu-8019. See this file in:
Directory listing for xnu-8019//osfmk/machine
Makefile
asm.h
atomic.h
commpage.h
config.h
cpu_affinity.h
cpu_capabilities.h
cpu_data.h
cpu_number.h
endian.h
io_map_entries.h
lock.h
locks.h
lowglobals.h
machine_cpu.h
machine_cpuid.h
machine_kpc.h
machine_perfmon.h
machine_remote_time.h
machine_routines.h
machine_rpc.h
machlimits.h
machparam.h
memory_types.h
monotonic.h
pal_hibernate.h
pal_routines.h
pmap.h
sched_param.h
setjmp.h
simple_lock.h
smp.h
task.h
thread.h
trap.h
vm_tuning.h