MFS12 r353047:

MFS12 r353047:
 MFC r353004, r353012:
 r353004:
  Explicitly add opensolaris_load="YES" to loader.conf through the
  installer when installing the system on a ZFS root filesystem.

  For arm64, zfs_load="YES" does not add opensolaris.ko as a kld
  dependency, so add it explicitly to prevent boot-time failures
  out-of-box.

 r353012:
  Add a comment explaining why the opensolaris_load line in loader.conf
  is explicitly added.

PR:		240478
Approved by:	re (kib)
Sponsored by:	Rubicon Communications, LLC (Netgate)