Holy crap, you can run it on XBox and PS4? How did he even test that? Did Microsoft and Sony send him a devkit?
I imagine the people who paid for the port provided access. I think he has a decent thing going with game companies paying to port here or port there, etc.
PS4 support is relatively trivial – tweaking a few #ifdefs to know about the platform and porting a Makefile. LuaJIT already has well-tuned x86-64 support.
The PS3/Xbox360 porting work is described here (search for “PS3”). Platform restrictions don’t permit the JIT, but the LuaJIT interpreter is hand-coded assembly that runs about 2x faster than the standard Lua interpreter.
The sheer number of platforms that LuaJIT supports astounds me.