Remove arguments arity check in mjsunit because it vastly slows down the tests.
Remove arguments arity check in mjsunit because it vastly slows down the tests.

R=mstarzinger@chromium.org
BUG=

Review URL: https://codereview.chromium.org/724133004

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#25353}

UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh