Plan.checkForAsyncCollection();
  private final void insertOverflow(int arity) {    if (VM_Interface.VerifyAssertions) VM_Interface._assert(arity == queue.getArity());    if (tail.NE(Queue.TAIL_INITIAL_VALUE)) {      closeAndEnqueueTail(arity);    }    tail = queue.alloc().add(bufferLastOffset(arity) + BYTES_IN_WORD);  }