MFC r315636,315876,316095:
Sync libarchive with vendor

Vendor changes/bugfixes (FreeBSD-related):
r315636:
PR 867 (bsdcpio): show numeric uid/gid when names are not found
PR 870 (seekable zip): accept files with valid ZIP64 EOCD headers
PR 880 (pax): Fix handling of "size" pax header keyword
PR 887 (crypto): Discard 3072 bytes instead of 1024 of first keystream
OSS-Fuzz issue 806 (mtree): rework mtree_atol10 integer parser
Break ACL read/write code into platform-specific source files

r315876:
Store extended attributes with extattr_set_link() if no fd is provided
Add extended attribute tests to libarchive and bsdtar
Fix tar's test_option_acls
Support the UF_HIDDEN file flag

r316095:
Constify variables in several places
Unify platform ACL code in a single source file
Fix unused variable if compiling on FreeBSD without NFSv4 ACL support

MFC r299529,r299540,r299576,r299896:

r299529,r299540:
Update libarchive to 3.2.0

New features:
- new bsdcat command-line utility
- LZ4 compression (in src only via external utility from ports)
- Warc format support
- 'Raw' format writer
- Zip: Support archives >4GB, entries >4GB
- Zip: Support encrypting and decrypting entries
- Zip: Support experimental streaming extension
- Identify encrypted entries in several formats
- New --clear-nochange-flags option to bsdtar tries to remove noschg and
similar flags before deleting files
- New --ignore-zeros option to bsdtar to handle concatenated tar archives
- Use multi-threaded LZMA decompression if liblzma supports it
- Expose version info for libraries used by libarchive

r299576,r299896:
Fix broken cpio behavior.

Relnotes: yes