FreeBSD highlights:
- Fix enforcement of UNIX permissions
- Fix enforcement of NFSv4 ACLs
- Fix Clang 11 build for 13-CURRENT
- Fix send/recv operations with a large number of snapshots/datasets
- Default to autotrim=on (fixes POLA)
- Automatic fallback to /boot/ to look for zpool.cache (fixes POLA)
- Fix l2arc_dev_rebuild_start thread name
- Create taskq threads in appropriate proc
- Restore ARC MFU/MRU pressure