[vectorIntrinsics] RFR: Some cleanups in Java code

[Paul Sandoz]

+1
Paul.

> On Mar 25, 2020, at 3:33 AM, Vladimir Ivanov <vladimir.x.ivanov at oracle.com> wrote:
> 
> http://cr.openjdk.java.net/~vlivanov/panama/vector/cleanup.01/webrev.00/
> 
> Some minor cleanups:
>  - remove unused opcodes
>  - remove redundant default implementations
>  - sprinkle additional @ForceInline annotations
> 
> Testing: jdk/incubator/vector tests
> 
> Best regards,
> Vladimir Ivanov