[vector] remove the saturate operations

[Paul Sandoz]

Hi,

This patch removes the saturate operations:

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

We concluded we are not ready to support this functionality, not even on helper methods, right now (such functionality is also not present on the Math class). This functionality may be better represented as a new vector species and/or boxed type (SaturatedInt).

Thanks,
Paul.