if (VM.VerifyAssertions) VM._assert(arity == queue.getArity());
if (VM_Interface.VerifyAssertions) VM_Interface._assert(arity == queue.getArity());
  private final boolean popOverflow(int arity) throws VM_PragmaNoInline {    if (VM.VerifyAssertions) VM._assert(arity == queue.getArity());    VM_Address sentinelAsAddress = VM_Address.zero().add(headSentinel(arity));    do {      if (!isReset())	queue.free(bufferStart(head));      VM_Address tmp = queue.dequeue(arity);      head = tmp.isZero() ? sentinelAsAddress : tmp;    } while (bufferOffset(head).isZero());    if (head.EQ(sentinelAsAddress))      return consumerStarved(arity);    else       return true;  }