MFV r310796, r310797:
Sync libarchive with vendor.
Vendor changes (relevant to FreeBSD):
PR #771: Add NFSv4 ACL support to pax and restricted pax
NFSv4 ACL information may now be stored to and restored from tar archives.
ACL must be non-trivial and supported by the underlying filesystem, e.g.
natively by ZFS or by UFS with the NFSv4 ACL enable flag set.
MFC after: 2 weeks
Relnotes: yes