Lua output contains lots of global variables

Hello, and thank you for this fantastic programming language.

I noticed that the produced Lua output generates a lot of globals. In Lua, as soon as a function is not prefixed with `local` then it is automatically considered to be global. There are a lot of variables like that in the `_lua` folder, where I think the minimum runtime is defined. Will it be possible to make sure those are not transformed into globals? Developing plugins using Lua that will pollute this much the global namespace is not desirable.

Thanks