12792 bhyve upstream sync 2020 May
Reviewed by: Mike Zeller <mike.zeller@joyent.com>
Approved by: Robert Mustacchi <rm@fingolfin.org>

12775 reorganize bhyve contrib headers
Reviewed by: Rich Lowe <richlowe@richlowe.net>
Reviewed by: Andy Fiddaman <omnios@citrus-it.co.uk>
Approved by: Robert Mustacchi <rm@fingolfin.org>