Revert of Preparse functions in the scope that was created when parsing of the function was started (patchset #2 id:20001 of https://codereview.chromium.org/2370713003/ )

Reason for revert:
Needed for https://codereview.chromium.org/2373443003/

Original issue's description:
> Preparse functions in the scope that was created when parsing of the function was started
>
> This reduces the number of scopes for lazily parsed top-level functions from 3 to 1
>
> BUG=v8:5209
>
> Committed: https://crrev.com/9618d095903c604a032b33792c068f4a6169503c
> Cr-Commit-Position: refs/heads/master@{#39725}

TBR=marja@chromium.org,verwaest@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:5209

Review-Url: https://codereview.chromium.org/2365393002
Cr-Commit-Position: refs/heads/master@{#39729}