This is xnu-8019. See this file in:
Directory listing for xnu-8019//bsd/dev/dtrace
Makefile
blist.c
blist.h
dtrace.c
dtrace_glue.c
dtrace_ptss.c
dtrace_subr.c
dtrace_xoroshiro128_plus.c
dtrace_xoroshiro128_plus.h
fasttrap.c
fbt.c
fbt_blacklist.c
lockprof.c
lockstat.c
profile_prvd.c
scripts/
sdt.c
sdt_subr.c
systrace.c
systrace.h