Provided patch to fix building x11/nvidia-driver* on #FreeBSD src main at commit 4dd828c80828637452a8a4e07a64e294c82e5d8b and later on Bug 288236.
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=288236
Also opened review for the patch as D51340, which is already accepted by 2 reviewers.
https://reviews.freebsd.org/D51340
As discussed with Konstantin on Bug 288236, turned out that formerly constant macros are now really "variables", the fix is applied conditionally.
As the above-mentioned commit does NOT have corresponding version bump, there are broken time window on main branch only before above-mentioned commit around 10 days.