MFH r324148:
Sync libarchive with vendor.

Relevant vendor changes:
PR #905: Support for Zstandard read and write filters
PR #922: Avoid overflow when reading corrupt cpio archive
Issue #935: heap-based buffer overflow in xml_data (CVE-2017-14166)
OSS-Fuzz 2936: Place a limit on the mtree line length
OSS-Fuzz 2394: Ensure that the ZIP AES extension header is large enough
OSS-Fuzz 573: Read off-by-one error in RAR archives (CVE-2017-14502)

Security: CVE-2017-14166, CVE-2017-14502

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