As of https://codereview.chromium.org/2348493003 there are no users of
this intrinsic left in the code, and we don't want to have any new users
of it. The runtime function remains as it serves as a fallback for the
optimized code (Crankshaft code actually).

BUG=v8:5049
R=mstarzinger@chromium.org

Review-Url: https://codereview.chromium.org/2378693002
Cr-Commit-Position: refs/heads/master@{#39822}