[Beignet] porting beignet to FreeBSD

[Rebecca N. Palmer]

Debian have a hybrid they call GNU/kFreeBSD (FreeBSD kernel but GNU C 
library) that can be run in a chroot or jail under FreeBSD: 
https://wiki.debian.org/Debian_GNU/kFreeBSD_FAQ#Q._Can_I_run_Debian_GNU.2FkFreeBSD_in_a_chroot_under_FreeBSD.3F

It includes beignet, but I don't know if anyone has tried to use that on 
it.  To use OpenCL in a chroot, the device (usually /dev/dri/card0) 
needs to be visible from inside, e.g. by bind-mounting /dev/dri.