Minimum supported version for -current

From: Warner Losh <imp_at_bsdimp.com>
Date: Sun, 10 Oct 2021 18:38:37 UTC
Greetings,

I've created https://reviews.freebsd.org/D32444 to bump the minimum
supported version
of FreeBSD to build current up to 11.3R. This will allow me to remove a
number of old
workarounds from Makefile.inc1 that are starting to get in the way due to
their sheer number.

Do people have a need to build FreeBSD -current from 10.x systems anymore?

Warner

P.S. I selected 11.3R because it's the most recent release to go
unsupported. I plan on
testing this release, but if there's issues, I'll post to this thread.