SI-8228 Avoid infinite loop with erroneous code, overloading

`isApplicableBasedOnArity` couldn't get of the ferris wheel after
as `followApply` kept insisting on another spin.

    scala> ErrorType nonPrivateMember nme.apply
    res0: $r.intp.global.Symbol = value apply

    scala> res0.info
    res1: $r.intp.global.Type = <error>

This commit makes `followApply` consider that an `ErrorType`
does not contain an `apply` member.

I also considered whether to do a deep check on the type
(`isErroneous`), but I can't motivate this with a test.
I tend to think we *shouldn't* do that: `List[${ErrorType}]`
still has an `apply` member that we should follow, right?
Merge pull request #3457 from retronym/ticket/8228

SI-8228 Avoid infinite loop with erroneous code, overloading