This commit updates to the latest version and enables LuaJIT on the architectures where we can. Neovim plugins require a very specific version of LuaJIT, so we statically embed it (for more discussion see: https://marc.info/?l=openbsd-ports&m=163153228730587&w=2). Also, make the build honour SEPARATE_BUILD. Thanks to upstream, and in particular Christian Clason, for helping me understand what needed to be done WRT LuaJIT. Tested sparc64 tb@. "looks OK to me" sthen@. OK paco@.