This is xnu-8019. See this file in:
Directory listing for xnu-8019//config
BSDKernel.arm.exports
BSDKernel.arm64.exports
BSDKernel.exports
BSDKernel.x86_64.exports
IOKit.arm.exports
IOKit.arm64.MacOSX.exports
IOKit.arm64.exports
IOKit.arm64.hibernation.MacOSX.exports
IOKit.exports
IOKit.x86_64.MacOSX.exports
IOKit.x86_64.exports
Kasan_disabled.exports
Kasan_enabled.exports
Kcov_disabled.exports
Kcov_enabled.exports
Libkern.arm.exports
Libkern.arm64.MacOSX.exports
Libkern.arm64.exports
Libkern.exports
Libkern.x86_64.MacOSX.exports
Libkern.x86_64.exports
MACFramework.arm.exports
MACFramework.arm64.exports
MACFramework.exports
MACFramework.x86_64.exports
MASTER
MASTER.arm
MASTER.arm64
MASTER.arm64.BridgeOS
MASTER.arm64.MacOSX
MASTER.arm64.bcm2837
MASTER.arm64.iPhoneOS
MASTER.x86_64
Mach.arm.exports
Mach.arm64.exports
Mach.exports
Mach.x86_64.exports
Makefile
MasterVersion
Private.arm.exports
Private.arm64.MacOSX.exports
Private.arm64.exports
Private.exports
Private.x86_64.exports
README.DEBUG-kernel.txt
System.kext/
Unsupported.arm.exports
Unsupported.arm64.MacOSX.exports
Unsupported.arm64.exports
Unsupported.exports
Unsupported.x86_64.MacOSX.exports
Unsupported.x86_64.exports
Unused.arm.exports
Unused.arm64.exports
Unused.exports
generate_combined_symbolsets_plist.sh
generate_linker_aliases.sh
generate_linker_exports.sh
generate_symbolset_plist.sh
list_supported.sh
newvers.pl
version.c