if (Assert.VERIFY_ASSERTIONS) Assert._assert((len.toInt() & (BYTES_IN_INT-1)) == 0 && (start.toInt() & (BYTES_IN_INT-1)) == 0);
  public static void zeroSmall(Address start, Extent len) throws InlinePragma {    Address end = start.add(len);    for (Address i = start; i.LT(end); i = i.add(BYTES_IN_INT))       i.store(0);  }