mq on kqueue broken after upgrade to FreeBSD 11

[Lewis Donzis]

> On Sep 30, 2016, at 5:44 PM, Alexander Kabaev <kabaev at gmail.com> wrote:
> No objection, but possible suggestion: if the primary use of this
> symbol is for tests and nothing else, maybe it does belong in
> FBSDprivate_1.0 FBSDprivate_1.0 section instead?

The primary use for us is definitely not testing — it appears to be the only way to get a handle that can be used with kevent().  In that regard, it would be even nicer if it was a regular mq_*() function, even if it had to be non-portable, rather than beginning with “__” which makes it look internal only.

lew