These operators are really pure on the JavaScript level, and were only
part of the effect chain to make sure we don't accidentially schedule
them right after raw allocations, which is no longer an issue since we
now have the concept of atomic regions.

R=jarin@chromium.org

Review URL: https://codereview.chromium.org/1893543004

Cr-Commit-Position: refs/heads/master@{#35552}