[REPL] Autocompletion of arguments inside `ModuleName.function` call is broken

[giordano]

On f0a2a7a, autocompletion of the arguments inside function calls of the form Module.function is broken, only keywords are suggested, not types, variables, functions, etc. For example:

M.f(p<TAB>

directly autocompletes to

M.f(primitive type

because primitive type is the only keyword starting with p. This is a regression, autocompletion in this situation used to work in previous versions.