Don't use synthetic companion methods to achieve this. The advantages of the direct
approach are:

 - it's overall simpler
 - it can be more easily extended to opaque types

resolve overload errors should be suppressed if some types are
already erroenous.

Distinguish what is printed by previous knowledge whether the
symbol is a term or a type.

Treat as abstract types until FirstTransform, as aliases afterwards

Open opaque types as gadts in opaque companion modules.

In the new implementation, a companion object of an opaque type

  opaque type T = A

only knows that T <: A and that A <: T. By itself that does not
propagate some informations from `A` to `T`. For instance the members
of A are now not the members of T.