VM_Interface._assert(bufferOffset(head).sGE(VM_Offset.fromInt(arity<<LOG_BYTES_IN_ADDRESS)));
VM_Interface._assert(bufferOffset(head).sGE(VM_Word.fromIntZeroExtend(arity).lsh(LOG_BYTES_IN_ADDRESS).toOffset()));
  protected final boolean checkPop(int arity) throws VM_PragmaInline {    if ((bufferOffset(head).isZero()) || isReset()) {      return popOverflow(arity);    } else {      if (VM_Interface.VerifyAssertions)        VM_Interface._assert(bufferOffset(head).sGE(VM_Offset.fromInt(arity<<LOG_BYTES_IN_ADDRESS)));      return true;    }  }