[luatex] \primitive and disabled primitives

[Will Robertson]

Hi Taco,

Let's say with this syntax to conditionally enable new primitives 
syntax I select just \primitive. What would
    \primitive\<any other LuaTeX primitive>
tell me?

I'm expecting that it would work as if the argument to \primitive 
wasn't actually a primitive (whether defined or not), but I just wanted 
to check.

Will