This is xnu-8019. See this file in:
Directory listing for xnu-8019//libsyscall/wrappers
__commpage_gettimeofday.c
__get_cpu_capabilities.s
_errno.h
_libc_funcptr.c
_libkernel_init.c
_libkernel_init.h
cancelable/
carbon_delete.c
clonefile.c
coalition.c
csr.c
fs_snapshot.c
gethostuuid.c
gethostuuid.h
gethostuuid_private.h
getiopolicy_np.c
guarded_open_dprotected_np.c
guarded_open_np.c
init_cpu_capabilities.c
ioctl.c
kdebug_trace.c
kern_debug.c
kill.c
legacy/
libproc/
mach_absolute_time.s
mach_approximate_time.c
mach_approximate_time.s
mach_boottime.c
mach_bridge_remote_time.c
mach_continuous_time.c
mach_get_times.c
mach_timebase_info.c
open-base.c
open_dprotected_np.c
persona.c
pid_shutdown_networking.c
posix_sem_obsolete.c
proc.c
quota_obsolete.c
reboot.c
remove-counter.c
rename.c
renameat.c
renamex.c
rmdir.c
select-base.c
setpriority.c
sfi.c
sigsuspend-base.c
skywalk/
spawn/
stackshot.c
string/
system-version-compat-support.c
system-version-compat-support.h
system-version-compat.c
terminate_with_reason.c
thread_register_state.c
unix03/
unlink.c
unlinkat.c
utimensat.c
varargs_wrappers.s
work_interval.c