This is xnu-8019. See this file in:
# options

OPTIONS/libkerncpp					optional libkerncpp
OPTIONS/kdebug						optional kdebug
OPTIONS/config_dtrace					optional config_dtrace
OPTIONS/hibernation					optional hibernation
OPTIONS/iotracking					optional iotracking
OPTIONS/networking					optional networking
OPTIONS/crypto						optional crypto
OPTIONS/zlib						optional zlib
OPTIONS/zlibc						optional zlibc

# libkern

libkern/gen/OSAtomicOperations.c			standard
libkern/gen/OSSpinLock.c				standard
libkern/gen/OSDebug.cpp					standard

libkern/c++/OSMetaClass.cpp				optional libkerncpp
libkern/c++/OSObject.cpp				optional libkerncpp

libkern/c++/OSArray.cpp					optional libkerncpp
libkern/c++/OSBoolean.cpp				optional libkerncpp
libkern/c++/OSCollection.cpp				optional libkerncpp
libkern/c++/OSCollectionIterator.cpp			optional libkerncpp
libkern/c++/OSData.cpp					optional libkerncpp
libkern/c++/OSDictionary.cpp				optional libkerncpp
libkern/c++/OSIterator.cpp				optional libkerncpp
libkern/c++/OSKext.cpp					optional libkerncpp
libkern/c++/OSNumber.cpp				optional libkerncpp
libkern/c++/OSOrderedSet.cpp				optional libkerncpp
libkern/c++/OSRuntime.cpp				optional libkerncpp
libkern/c++/OSRuntimeSupport.c				optional libkerncpp
libkern/c++/OSSerialize.cpp				optional libkerncpp
libkern/c++/OSSet.cpp					optional libkerncpp
libkern/c++/OSString.cpp				optional libkerncpp
libkern/c++/OSSymbol.cpp				optional libkerncpp
libkern/c++/OSUnserialize.cpp				optional libkerncpp
libkern/c++/OSUnserializeXML.cpp			optional libkerncpp
libkern/c++/OSSerializeBinary.cpp			optional libkerncpp

libkern/c++/priority_queue.cpp				standard

libkern/coreanalytics/coreanalytics_shim.cpp		standard
libkern/OSKextLib.cpp					optional libkerncpp
libkern/mkext.c						standard
libkern/OSKextVersion.c					standard

libkern/net/inet_aton.c					standard
libkern/net/inet_ntoa.c					standard
libkern/net/inet_ntop.c					standard
libkern/net/inet_pton.c					standard

libkern/stdio/scanf.c					standard

libkern/uuid/uuid.c					standard

libkern/os/log.c					standard
libkern/os/log_encode.c					standard
libkern/os/log_mem.c					standard
libkern/os/log_queue.c					standard
libkern/os/object.c					standard
libkern/os/internal.c					standard
libkern/os/refcnt.c					standard

libkern/kernel_mach_header.c                            standard

libkern/zlib/adler32.c                                  optional zlib
libkern/zlib/compress.c                                 optional zlib
libkern/zlib/z_crc32.c                                  optional zlib
libkern/zlib/deflate.c                                  optional zlib
libkern/zlib/infback.c                                  optional zlib
libkern/zlib/inffast.c                                  optional zlib
libkern/zlib/inflate.c                                  optional zlib
libkern/zlib/inftrees.c                                 optional zlib
libkern/zlib/trees.c                                    optional zlib
libkern/zlib/uncompr.c                                  optional zlib
libkern/zlib/zutil.c                                    optional zlib

libkern/zlib/adler32.c                                  optional zlibc
libkern/zlib/compress.c                                 optional zlibc
libkern/zlib/z_crc32.c                                  optional zlibc
libkern/zlib/deflate.c                                  optional zlibc
libkern/zlib/infback.c                                  optional zlibc
libkern/zlib/inffast.c                                  optional zlibc
libkern/zlib/inflate.c                                  optional zlibc
libkern/zlib/inftrees.c                                 optional zlibc
libkern/zlib/trees.c                                    optional zlibc
libkern/zlib/uncompr.c                                  optional zlibc
libkern/zlib/zutil.c                                    optional zlibc

libkern/crypto/register_crypto.c		optional crypto
libkern/crypto/corecrypto_sha2.c		standard
libkern/crypto/corecrypto_sha1.c		optional crypto
libkern/crypto/corecrypto_md5.c			optional crypto
libkern/crypto/corecrypto_des.c			optional crypto
libkern/crypto/corecrypto_aes.c			optional crypto
libkern/crypto/corecrypto_aesxts.c		optional crypto
libkern/crypto/corecrypto_rand.c		optional crypto
libkern/crypto/corecrypto_rsa.c		    optional crypto
libkern/crypto/corecrypto_chacha20poly1305.c	optional	crypto

libkern/coretrust/coretrust.c   standard

libkern/apple_encrypted_archive/apple_encrypted_archive.c	standard

libkern/img4/interface.c 		standard

libkern/amfi/amfi.c 		standard

libkern/stack_protector.c       standard
libkern/ptrauth_utils.c         standard

libkern/kxld/kxld.c             optional config_kxld
libkern/kxld/kxld_array.c       optional config_kxld
libkern/kxld/kxld_copyright.c   optional config_kxld
libkern/kxld/kxld_demangle.c    optional config_kxld
libkern/kxld/kxld_dict.c        optional config_kxld
libkern/kxld/kxld_kext.c        optional config_kxld
libkern/kxld/kxld_reloc.c       optional config_kxld
libkern/kxld/kxld_object.c      optional config_kxld
libkern/kxld/kxld_sect.c        optional config_kxld
libkern/kxld/kxld_seg.c         optional config_kxld
libkern/kxld/kxld_srcversion.c  optional config_kxld
libkern/kxld/kxld_splitinfolc.c optional config_kxld
libkern/kxld/kxld_sym.c         optional config_kxld
libkern/kxld/kxld_symtab.c      optional config_kxld
libkern/kxld/kxld_util.c        optional config_kxld
libkern/kxld/kxld_uuid.c        optional config_kxld
libkern/kxld/kxld_versionmin.c  optional config_kxld
libkern/kxld/kxld_vtable.c      optional config_kxld

libkern/libclosure/runtime.cpp      optional config_blocks
libkern/libclosure/libclosuredata.c optional config_blocks