jumper, gather_f16

Here we use 64-bit gather instructions for HSW,
which I think we haven't done before.

Change-Id: I7b22b3cc0b7a151952518bb9afb90624ebdb4a22
Reviewed-on: https://skia-review.googlesource.com/11602
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Mike Klein <mtklein@chromium.org>
5 files changed