Revert of Remove --ignition-staging to --ignition-osr implication. (patchset #1 id:1 of https://codereview.chromium.org/2298613003/ )

Reason for revert:
Re-enable to get new data after recent changes.

Original issue's description:
> Remove --ignition-staging to --ignition-osr implication.
>
> Ignition OSR to turbofan seems to cause instruction selector crashes
> (where instructions selector gets simplified operators, probably
> because we break the effect chain somehow).
>
> BUG=chromium:641893
>
> Committed: https://crrev.com/26df3e230ebd8c7d1cd95ea54155959eee7cb830
> Cr-Commit-Position: refs/heads/master@{#39045}

TBR=bmeurer@chromium.org,jarin@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=chromium:641893

Review-Url: https://codereview.chromium.org/2318943002
Cr-Commit-Position: refs/heads/master@{#39231}