This adds support for i32.rem_u and i32.rem_s, implemented on ia32 and
x64.

R=ahaas@chromium.org

Bug: v8:6600
Change-Id: Id08a51f7a0dcb7a1ed43c5a97be7a7dafff85397
Reviewed-on: https://chromium-review.googlesource.com/1023932Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52764}