Using the dedicated simplified operator we are able to eliminate
redundant neuterung checks as long as there is no call in the
effect chain. This yields a nice speed up for the Octane Mandreel
benchmark (and TypedArray-heavy workloads in general).

R=jarin@chromium.org
BUG=v8:5267

Review-Url: https://codereview.chromium.org/2279213002
Cr-Commit-Position: refs/heads/master@{#38932}