Dependent function types: self.type and this.type not the same

[b-studios]

minimized code

trait Foo { self =>
  type M
  def apply(prog: (h: self.type) => h.M): M = prog(this)
}

expectation

The above code example type checks. When replacing self.type with this.type I am getting the following error:

type M is not a member of <refinement>

However, I expect self.type and this.type to be the same.

[abgruszecki]

See also the potentially-related #6635.

[b-studios]

The issue still occurs with 0.18.0-bin-20190812-0ebbcff-NIGHTLY