Latest commit on the upstream repository is from May, 27 - I think the binaries are pretty close to the 'lastest version'. You can check when the binary was built and from which commit, just to compare with the upstream repo (https://github.com/libretro/mame).
Ah, I see that now. Looks like they're dealing with one heck of a pull request. I'll keep an eye on the upstream repo. Cheers, and thanks!