The practical use for this should be very limited because I don't
think anyone should change `lib`, let alone change `lib.functionArgs`,
but, but it would be even stranger to rely on `args.lib` (or really
`specialArgs.lib` for what's clearly a behavior of the current
`evalModules`, which uses its own ambient lib for basically everything.
The shadowing of `lib` by `args.lib` here seems to be a small mistake,
which is easy to make.
