Style(9): Allow // comments

From: Warner Losh <imp_at_bsdimp.com>
Date: Tue, 26 Jul 2022 21:03:34 UTC
So, is it time to allow C++ comments? I think so.

https://reviews.freebsd.org/D35960

Comments about how I said it? In the review.
Comments on whether or not we should do it? Reply here.

Warner