MFV: xz-embedded 3f438e15109229bb14ab45f285f4bff5412a9542MFC after: 2 weeks
MFV r262756:Import xz-embedded from git.This is from commit hash '6a8a2364434763a033781f6b2a605ace9a021013'.This makes it possible to use CRC64 but for now it's intentionallynot added to build.
Update contrib/xz-embedded to build with new GEOM_UNCOMPRESS module.Approved by: adrian (mentor)
Initial copy of xz-embedded to sys/contrib/.The upcoming geom_compress module (a read-only gzip/ulzma translation layer,similar to what geom_uzip does) will leverage parts of this.