Issue with this in presence of self alias

[OndrejSpanel]

When a self alias is declared for a class, this.modify cannot be compiled, instead it results in error:

Unsupported source object: must be a case class or sealed trait, but got: val <none>

Code:

  case class State(x: Int) {self =>

    def mod: State = this.modify(_.x).setTo(1)
  }

This PR adds test demonstrating this issue.

It is quite likely the issue is closely related to #97

[OndrejSpanel]

Note: the fix from #97 does not seem to have any effect on this issue.

[KacperFKorban]

Ok, I see what the issue is.
If we create a self type the type of this gets those 'refinements' added to its type. So obj.tpe.widen is an AndType in this case.

I can make a PR to fix it, but I'll wait for #97 to be merged, since it requires changes in similar places.

[adamw]

@KacperFKorban merged :)

[KacperFKorban]

I couldn't rebase this branch or push commits here. (since I don't have write access to the repo)
So I created a new PR and rebased it on top of this one -> #99