I promise that this was a genuine case of parallel evolution – I didn't read any LuaJIT source or documentation while writing the code or article.
Afterwards, I searched for "reverse linear scan register allocation", discovered the blog post which referenced LuaJIT, and linked it in the text.
I've updated the article to move the LuaJIT reference to the top, and adjusted the phrasing to be clear that this is not an invention, it's simply an interesting implementation. What you call "naive", others may consider didactic :)
Let me know if you have other feedback or suggested changes, either here or via email (in my profile).