MFV r339640,339641,339644:

MFV r339640,339641,339644:
Sync libarchive with vendor

Relevant vendor changes:
  PR #1013: Add missing h_base offset when performing absolute seeks in
            xar decompression
  PR #1061: Add support for extraction of RAR v5 archives
  PR #1066: Fix out of bounds read on empty string filename for gnutar, pax
            and v7tar
  PR #1067: Fix temporary file path buffer overflow in tests
  IS #1068: Correctly process and verify integer arguments passed to
            bsdcpio and bsdtar
  PR #1070: Don't default XAR entry atime/mtime to the current time

MFC after:	1 month