This will be committed in two parts. Flag field resizing and renumbering prevents the vnode from growing with later addition of v_nchash and will be committed first.
This significantly speeds up path lookup, Cascade Lake doing access(2) on ufs on /usr/obj/usr/src/amd64.amd64/sys/GENERIC/vnode_if.c, ops/s:
before: average:2535298
after: average:279762
That is +10%.
The reversed order of computation here does not seem to matter. I dumped the namecache populated with > 7 mln and recomputed chain placement with both methods, almost no differences.