This is xnu-10002.1.13. See this file in:
######################################################################
#BEGIN	Machine dependent Makefile fragment for x86_64
######################################################################

CWARNFLAGS = $(CWARNFLAGS_STD) -Wno-atomic-implicit-seq-cst

# Files that must go in the __HIB segment:
UNCONFIGURED_HIB_FILES=					\
           WKdmDecompress_new.o         \
           WKdmData_new.o               \
           hibernate_restore.o          \
           bcopy.o			\
           bzero.o

HIB_FILES=$(filter $(UNCONFIGURED_HIB_FILES),$(OBJS))

# Unconfigured __HIB files must be Mach-O for "setsegname"
WKdmDecompress_new.o_CFLAGS_ADD += -fno-stack-protector -fno-stack-check $(CFLAGS_NOLTO_FLAG)
WKdmData_new.o_CFLAGS_ADD += -fno-stack-protector -fno-stack-check $(CFLAGS_NOLTO_FLAG)
hibernate_restore.o_CFLAGS_ADD += -fno-stack-protector -fno-stack-check $(CFLAGS_NOLTO_FLAG)
bcopy.o_CFLAGS_ADD += -fno-stack-protector -fno-stack-check $(CFLAGS_NOLTO_FLAG)
bzero.o_CFLAGS_ADD += -fno-stack-protector -fno-stack-check $(CFLAGS_NOLTO_FLAG)
fp_simd.o_SFLAGS_ADD += -mavx512f

# To appear at the beginning of the __HIB segment, emit
# as Mach-O so that the linker can enforce symbol order
boot_pt.o_CFLAGS_ADD += $(CFLAGS_NOLTO_FLAG)

# fast path lock C leaf functions must be built without stack frames
locks_i386_opt.o_CFLAGS_ADD += -momit-leaf-frame-pointer -O2
ifeq ($(KASAN),1)
# rdar://92180818: the fakestack implementation uses ticket locks
# so we need to disable stack use-after-return checks, to avoid deadlocks.
lock_ticket.o_CFLAGS_ADD += -fsanitize-address-use-after-return=never
endif

######################################################################
#END	Machine dependent Makefile fragment for x86_64
######################################################################