[vector] Vector Cast Tests

[Paul Sandoz]

Looks good.

Unless you have plans at some point soonish i can take a stab at writing load/store tests.

Paul.

> On Apr 16, 2018, at 6:28 PM, Lupusoru, Razvan A <razvan.a.lupusoru at intel.com> wrote:
> 
> Hi everyone,
> 
> I have created tests for cast - and because casts can go from every element and shape to another, there are quite a lot of tests. To simplify my implementation of the base test along with debugging once something fails, I chose to create all 36 combinations of test from one type to the other (which are still parameterized by shape). Let me know what your thoughts are!
> 
> http://cr.openjdk.java.net/~rlupusoru/panama/webrev_casttests_00/
> 
> Thanks,
> Razvan
>