[vector] RFR 8218750: Vectorized ChaCha20 Benchmark

[Adam Petcher]

New webrev: https://cr.openjdk.java.net/~apetcher/8218750/webrev.02/

On 2/12/2019 1:08 PM, Vladimir Ivanov wrote:
>
> I suggest to shape it as follows:
>
>   private ChaChaVector cc20_S128 = new 
> ChaChaVector(Vector.Shape.S_128_BIT);
>
>   @Benchmark
>   public void encrypt128() {
>       cc20_S128.chacha20(key, nonce, counter, in, out);
>   }
>
> As I understand, ChaChaBench.runKAT is a unit test. You can put it 
> either into ChaChaBench.setup() or leave in ChaChaBench ctor, but use 
> cc20_S128/S256/S512 instead.

I believe I reorganized it as you suggested. I added a helper method 
that invokes runKAT when each ChaChaVector object is constructed.