Intersection of by-name and singleton type as result of application

[gsps]

The following code produces an error complaining about cond.type not being stable. In the subsequent function application we nonetheless try to compute the intersection of non-value type => Boolean and Singleton, which is caught by an assertion in AndType.

object Crash {
  def f(cond: => Boolean): cond.type = ???
  f(true)
}