[vector] Intrinsics for fromByteArray, fromByteBuffer, intoByteArray, intoByteBuffer

[Lupusoru, Razvan A]

Hi everyone,

I have implemented intrinsics for fromByteArray and fromByteBuffer along with their store equivalents. These were tested locally in a limited fashion but since they use existing tested functionality of load/store, I do not expect any issues.

Please take a look and let me know if you see any issues. Thanks!
http://cr.openjdk.java.net/~rlupusoru/panama/webrev_frombytearr_01/

--Razvan