int idx = VM_Magic.objectAsType(tib[0]).getTibSlot() << TIB_SHIFT;
int idx = VM_Magic.objectAsType(tib[0]).getTibOffset().rsh(LOG_BYTES_IN_INT).toInt() << TIB_SHIFT;
  public static void setTIB(Object ref, Object[] tib) throws InlinePragma {    int idx = VM_Magic.objectAsType(tib[0]).getTibSlot() << TIB_SHIFT;    if (VM.VerifyAssertions) VM._assert((idx & TIB_MASK) == idx);    int tibWord = (VM_Magic.getIntAtOffset(ref, TIB_OFFSET) & ~TIB_MASK) | idx;    VM_Magic.setIntAtOffset(ref, TIB_OFFSET, tibWord);  }