[vector] Remove Vector.fromValues

[Paul Sandoz]

Hi,

Please review the following that removes Vector.fromValues:

  http://cr.openjdk.java.net/~psandoz/panama/vector-rm-fromValues/webrev/ <http://cr.openjdk.java.net/~psandoz/panama/vector-rm-fromValues/webrev/>

This method is not well optimized and it likely never will be particularly efficient since constructing a vector from values through a temporary buffer or explicit insertion will have a cost.   

The workaround is to use fromArray or the explicit withLane, which I think is fine for constructing vector constants (those constant within a loop or otherwise), and bring to the foreground the potential costs.

Paul.