Draft: Tiny tweak to printing of `IfaceFunTy`

Previously, depending on what width you had, a function type would get printed as one of:

1. type1 -> type2 -> ... -> typen

2. type1
   -> type2 -> ... -> typen

3. type1
   -> type2
   ...
   -> typen

After this change, we go straight from option 1 to option 3. This is somewhat user facing since this is the code that affects how GHCi prints types.