recur module (PUP-8610)

init.pp

plan recur() {
  recur::recurf(0, 0)
}

recurf.pp

function recur::recurf($i, $time) {
  $now = now()
  $delta = $now - $time
  notice("iteration ${i}: ${delta}")
  if $i < 250 {
    recur::recurf($i + 1, $now)
  }
}