RFR: 8264109: Add vectorized implementation for VectorMask.andNot()

[Xiaohong Gong]

Currently "VectorMask.andNot()" is not vectorized:
    public VectorMask<E> andNot(VectorMask<E> m) {
        // FIXME: Generate good code here.
        return bOp(m, (i, a, b) -> a && !b);
    }
This can be implemented with` "and(m.not())" `directly. Since `"VectorMask.and()/not()" `have been vectorized in hotspot, `"andNot"`
can be vectorized as well by calling them.

The performance gain is >100% for such a simple JMH:
  @Benchmark
  public Object andNot(Blackhole bh) {
    boolean[] mask = fm.apply(SPECIES.length());
    boolean[] r = fmt.apply(SPECIES.length());
    VectorMask<Byte> rm = VectorMask.fromArray(SPECIES, r, 0);

    for (int ic = 0; ic < INVOC_COUNT; ic++) {
      for (int i = 0; i < mask.length; i += SPECIES.length()) {
        VectorMask<Byte> vmask = VectorMask.fromArray(SPECIES, mask, i);
          rm = rm.andNot(vmask);
        }
    }
    return rm;
  }

-------------

Commit messages:
 - 8264109: Add vectorized implementation for VectorMask.andNot()

Changes: https://git.openjdk.java.net/jdk/pull/3211/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=3211&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8264109
  Stats: 11 lines in 2 files changed: 2 ins; 6 del; 3 mod
  Patch: https://git.openjdk.java.net/jdk/pull/3211.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/3211/head:pull/3211

PR: https://git.openjdk.java.net/jdk/pull/3211