VM_Interface._assert(bufferOffset(head).sGE(VM_Offset.fromInt(BYTES_IN_ADDRESS)));
VM_Interface._assert(bufferOffset(head).sGE(VM_Offset.fromIntZeroExtend(BYTES_IN_ADDRESS)));
  protected final VM_Address uncheckedPop() throws VM_PragmaInline {    if (VM_Interface.VerifyAssertions)       VM_Interface._assert(bufferOffset(head).sGE(VM_Offset.fromInt(BYTES_IN_ADDRESS)));    head = head.sub(BYTES_IN_ADDRESS);    // if (VM_Interface.VerifyAssertions) enqueued--;    return VM_Magic.getMemoryAddress(head);  }