Reland of write scopes of non-simple default arguments (patchset #1 id:1 of https://codereview.chromium.org/2081323006/ )

Reason for revert:
Infra issue appears to be over

TBR=adamk@chromium.org

Original issue's description:
> Revert of Rewrite scopes of non-simple default arguments (patchset #5 id:80001 of https://codereview.chromium.org/2077283004/ )
>
> Reason for revert:
> Seems to close tree (but it could be an infra issue)
>
> Original issue's description:
> > Rewrite scopes of non-simple default arguments
> >
> > Default parameters have additional declaration block scopes inserted
> > around them when something in the function scope calls eval. This
> > patch sets the parent scope of the expressions introduced due to
> > those defaults to the new block scope.
> >
> > R=adamk
> > BUG=chromium:616386
> >
> > Committed: https://crrev.com/0e14baf712955a1993f742647bb2adc293702b80
> > Cr-Commit-Position: refs/heads/master@{#37198}
>
> TBR=adamk@chromium.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=chromium:616386
>
> Committed: https://crrev.com/dd50262933d2ac087da32be887a7c18385fd998e
> Cr-Commit-Position: refs/heads/master@{#37201}

TBR=adamk@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:616386

Review-Url: https://codereview.chromium.org/2086353003
Cr-Commit-Position: refs/heads/master@{#37202}