null asInstance of Nothing not always throwing

[nicolasstucki]

In the following code the cast to Nothing does not throw the expected NullPointerException

def f: Unit = {
  val a: Nothing = null.asInstanceOf[Nothing] // No exception
}

but it does in

def f: Unit = {
  val a: Nothing = null.asInstanceOf[Nothing]
  println(a) // throws here
}

def f: Unit = {
  val a: Int = null.asInstanceOf[Nothing] // throws here
}

def f: Unit = {
  null.asInstanceOf[Nothing] // throws here
}

This issue was metioned prevoiusly in #1002.

[nicolasstucki]

def f: Unit = {
  val a: Nothing = null.asInstanceOf[Nothing] // No exception
}

with -optimise throws, that was how I discovered the issue.