NetBSD: a new version of the CDDL dtrace and ZFS code

This makes NetBSD the 6th OpenZFS platform, after Illumos, FreeBSD, Linux, Mac OS X and OSv. The 7th if you include the under development Windows port:

https://github.com/openzfsonwindows/ZFSin

This is an update, ZFS was first included in NetBSD in 2009.

But has never been stable. The root device vops look-up would cause kernel panics. Never worked out why. There has been some new efforts to make it useable though.

>this version is based on FreeBSD svn r315983"

For anyone interested, I believe these are the relevant CDDL dtrace/zfs components from that revision of FreeBSD, from early 2017: https://svnweb.freebsd.org/base/head/sys/cddl/?pathrev=31598...

Nice! Good job Netbsd!