3561 arc_meta_limit should be exposed via kstats
3116 zpool reguid may log negative guids to internal SPA history
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Gordon Ross <gordon.ross@nexenta.com>
Approved by: Garrett D'Amore <garrett@damore.org>