private static final int hash(long h) {
    h ^= (h>>>20) ^ (h>>>12);
    h ^= (h>>> 7) ^ (h>>> 4);
    h += h<<7; // smear low bits up high, for hashcodes that only differ by 1
    return (int)h;
  }
Auto-boxing version of {@link #replace}.
jctools-core/src/main/java/org/jctools/maps/NonBlockingHashMapLong.java