static boolean testMarkBit(VM_Address ref, int value) throws VM_PragmaUninterruptible { return (VM_Interface.readAvailableBitsWord(ref) & value) != 0;
static boolean testMarkBit(VM_Address ref, VM_Word value) throws VM_PragmaUninterruptible { return !(VM_Interface.readAvailableBitsWord(ref).and(value).isZero());
  static boolean testMarkBit(VM_Address ref, int value) throws VM_PragmaUninterruptible {    return (VM_Interface.readAvailableBitsWord(ref) & value) != 0;  }