MFC: r253983-253984
MFV: r262443

	Update BIND to 9.8.7

Note this is a commit straight to stable as BIND no longer exists in head.

Sponsored by:	DK Hostmaster A/S
MFC: r262333

Simplify the way the end of a singly linked list is followed (for adding
items), so it is more obvious that we aren't going to indirect through
a NULL pointer.

PR:             144723
Submitted by:   Garrett Cooper <yaneurabeya at gmail.com>
Obtained from:  NetBSD r1.19