MFC r270215: Add missing break.

MFC r269873:
Fix broken pointer overflow check ns_name_unpack()

Many compilers may optimize away the overflow check `msg + l < msg',
where `msg' is a pointer and `l' is an integer, because pointer
overflow is undefined behavior in C.

Use a safe precondition test `l >= eom - msg' instead.

Reference:
https://android-review.googlesource.com/#/c/50570/

Requested by: pfg
Obtained from: NetBSD (CVS rev. 1.10)

MFC r269867:
Update our stub resolver to final version of libbind
(libbind-6.0).

Obtained from: ISC

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

This commit was generated by cvs2svn to compensate for changes in r174223,
which included commits to RCS files with non-trunk default branches.

Merge BIND 9.4.1 into main chunk.

MFC after: 2 weeks

This commit was generated by cvs2svn to compensate for changes in r170242,
which included commits to RCS files with non-trunk default branches.

Use C comments since we now preprocess these files with CPP.

Upgrade res_update(3) and the friends to BIND9's one excluding TSIG
support.

X-MFC after: never

It's not enough to provide symbol map files; you also have to add them
to ${SYM_MAPS}. This unbreaks world with SYMVER_ENABLED.

Pointy hat to: ume

- Merge our local changes.
- Exclude unnecessary functions for us.

This commit was generated by cvs2svn to compensate for changes in r156952,
which included commits to RCS files with non-trunk default branches.