class Opal::Rewriters::ThrowerFinder

rescue node.
ensure node should expect a rescue-else inside a
above a rescue. This logic is about tracking if a given
Otherwise we handle it in rescue. ensure is always
rescue. If ensure is present, we handle it in ensure.
In Opal we handle rescue-else either in ensure or in

def on_ensure(node)
  pushing([@rescue_else_stack, node]) { super }
end