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

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFV r248590,248594:
Update libarchive to 3.1.2

Some of new features:
- support for lrzip and grzip compression
- support for writing tar v7 format
- b64encode and uuencode filters
- support for __MACOSX directory in Zip archives
- support for lzop compresion (external utility)

Update libarchive's vendor dist to version 3.1.2 from release branch.

Git branch: release
Git commit: 19f23e191f9d3e1dd2a518735046100419965804

Obtained from: https://github.com/libarchive/libarchive.git