Revert of Store SharedFunctionInfos of a Script in a FixedArray indexed by their ID (patchset #11 id:190001 of https://codereview.chromium.org/2547483002/ )

Reason for revert:
LiveEdit is broken in some cases.

Original issue's description:
> Store SharedFunctionInfos of a Script in a FixedArray indexed by their ID
>
> Now that SharedFunctionInfos have a unique ID (and the IDs are dense),
> we can use them as an index into an array, instead of using a
> WeakFixedArray where we have to do a linear scan.
>
> Hooking up liveedit is a bit more involved, see
> https://docs.google.com/presentation/d/1FtNa3U7WsF5bPhY9uGoJG5Y9hnz5VBDabfOWpb4unWI/edit
> for an overview
>
> BUG=v8:5589
> R=verwaest@chromium.org,jgruber@chromium.org
>
> Committed: https://crrev.com/6595e7405769dc9d49e9568d61485efc6d468baf
> Cr-Commit-Position: refs/heads/master@{#41600}

TBR=jgruber@chromium.org,verwaest@chromium.org,yangguo@chromium.org,jochen@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=v8:5589,chromium:673950
NOPRESUBMIT=true

Review-Url: https://codereview.chromium.org/2578433002
Cr-Commit-Position: refs/heads/master@{#41684}