[vectorIntrinsics] Benchmark related fixes

[Paul Sandoz]

+1

Paul.

> On Apr 13, 2020, at 4:46 PM, Viswanathan, Sandhya <sandhya.viswanathan at intel.com> wrote:
> 
> Please find below a webrev which fixes two failures observed while running benchmarks:
> http://cr.openjdk.java.net/~sviswanathan/vectorIntrinsics/Benchfix/wenrev.00/ <http://cr.openjdk.java.net/~sviswanathan/vectorIntrinsics/Benchfix/wenrev.00/>
>  
> ChaChaBench: java.lang.UnsupportedOperationException: ROL: operator is not implemented
> The fix is in the Vector API Java implementation: Call opcode() after handling operators like ROL/ROR etc.
> ByteScalar.gather/scatter: java.lang.ArrayIndexOutOfBoundsException: Index 1071 out of bounds for length 1024
> The fix is in the scalar benchmarks adjusting the index value to not go out of bounds.
>  
> Best Regards,
> Sandhya
> ]