This test used to run 10M loop iterations to trigger OSR. Let's run 5
instead and trigger OSR manually through the runtime.

Bug: v8:7093
Change-Id: Ie0cdb9389ca465bf433e81a17fa60c300edc3e29
Reviewed-on: https://chromium-review.googlesource.com/785693
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49579}