This adds support for i64.div_s, i64.div_u, i64.rem_s, and i64.rem_u.

R=ahaas@chromium.org

Bug: v8:6600
Change-Id: I37e564684b278c8d2f664a859851c67f4bd83190
Reviewed-on: https://chromium-review.googlesource.com/1027612Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52785}