[vector] Vector Cast Tests

[Lupusoru, Razvan A]

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