sys/queue.h: Add {LIST,TAILQ}_REPLACE().

MFC after: 1 week
Obtained from: NetBSD
Sponsored by: Klara, Inc.
Reviewed by: cperciva, imp
Differential Revision: https://reviews.freebsd.org/D44679

(cherry picked from commit 7f479dee48973541da8c869b888b953161301c3b)

sys/queue.h: Whitespace cleanup.

MFC after: 1 week
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D44678

(cherry picked from commit 69fd60f1ead5a86eeb0b18847dd71f7ae3fce4a0)