case class C(x: Any)
class Test {
  def test(a: Any) = a match {
    case C("a") =>
    case C(x) => () => x
    // Patmat's CSE stores the results of the `asInstanceOf[C]` in a var
    // under -optimize, it doesn't bind a local for x at the beginning of the case body,
    // and instead selects temp.x from the closure body. This incurs an `ObjectRef`,
    // even though the closure only needs read only access.
    
    // Workaround: No ObjectRef needed in this case.
    // case C(x) => val xx = x; () => xx
  }
}