This was actually only necessary for dealing with %_Arguments and
%_ArgumentsLength in Crankshaft, which have been removed recently,
so there's no need to keep this piece of awesomeness around any
longer.

R=jarin@chromium.org

Review URL: https://codereview.chromium.org/1695193003

Cr-Commit-Position: refs/heads/master@{#34015}