Fix type inferencing for resolve strategy Closure.DELEGATE_ONLY

[eric-milles]

Consider the following:

class A {}
class B {
  def m(@DelegatesTo(value=A, strategy=Closure.DELEGATE_ONLY) Closure block) {
    ...
  }
  def x() {
    m // delegate is A, owner is B
      delegate
      owner
    }
  }
}

"delegate:, "owner" and other members of Closure are showing as unknown (underlined). DELEGATE_ONLY should skip owner but still resolve against the enclosing closure.