Reland of Immediately cache compiled scripts. (patchset #1 id:1 of https://codereview.chromium.org/1882833006/ )

Reason for revert:
Fixed webkit_unit_tests

Original issue's description:
> Revert of Immediately cache compiled scripts. (patchset #2 id:20001 of https://codereview.chromium.org/1890083002/ )
>
> Reason for revert:
> [Sheriff] Breaks:
> https://build.chromium.org/p/client.v8/builders/V8%20Linux64%20-%20debug/builds/8769
>
> Auto-bisect points to this CL.
>
> Original issue's description:
> > Immediately cache compiled scripts.
> >
> > Usually, script compilation is expensive enough to warrant the extra
> > overhead of caching scripts immediatly.
> >
> > BUG=chromium:588900
> > R=yangguo@chromium.org
> > LOG=n
> >
> > Committed: https://crrev.com/3533c084d470912384988768c4b3b109304da357
> > Cr-Commit-Position: refs/heads/master@{#35527}
>
> TBR=yangguo@chromium.org,jochen@chromium.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=chromium:588900
>
> Committed: https://crrev.com/f8a5a4da70d0a8e6dbb1b5c633c2b6b47fe5c3f6
> Cr-Commit-Position: refs/heads/master@{#35536}

TBR=yangguo@chromium.org,machenbach@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=chromium:588900
LOG=n

Review URL: https://codereview.chromium.org/1901573002

Cr-Commit-Position: refs/heads/master@{#35566}