Type and proc defs should conflict

```
/datum/proc/beep()
    return

/datum/test/beep
  var/thing = 1

/datum/test/beep()
    return
```

byond doesn't draw distinctions between class and proc defs, so you can't have a class with the same name as a proc.

in this example, `/datum/test/beep()` is the function def, and `/datum/test/beep` tries to redefine it (in BYOND)

See: https://www.byond.com/forum/post/2983339