In recent days there have been a number of Mesa commits for improving the OpenBSD (and FreeBSD) support for the user-space Mesa/Gallium3D drivers for these BSD operating systems.
Over the night, there were five more Mesa commits that improve OpenBSD support, including proper OpenBSD support within Mesa's configure.ac file. The BSD activity can be found via this CGit query.
The improved OpenBSD Mesa support comes months after they deemed their Intel DRM/KMS driver ready and also made adjustments to the Intel X.Org driver. The DRM/KMS drivers for Radeon and Nouveau on OpenBSD aren't as far along as the Intel support.
Outside of OpenBSD, there's ongoing improved Mesa FreeBSD support as part of the ongoing Radeon DRM porting going on for that BSD platform.