This also adds ObjectIsInteger and NumberIsInteger
operators.

Bug: v8:7340, v8:7250
Change-Id: I8067276d12c8532931f90e6397f8435362c2f9af
Reviewed-on: https://chromium-review.googlesource.com/951602Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51991}