Revert of Debugger: use list to find shared function info in a script. (patchset...

Revert of Debugger: use list to find shared function info in a script. (patchset #2 id:20001 of https://codereview.chromium.org/1206573004/)

Reason for revert:
[Sheriff] Breaks layout tests:
http://build.chromium.org/p/client.v8.fyi/builders/V8-Blink%20Linux%2064/builds/682

Original issue's description:
> Debugger: use list to find shared function info in a script.
>
> Now that we keep tabs on shared function infos from a script, we can speed up finding shared function infos for debugging. However, in case we have to compile a function that cannot be lazily compiled without context, we fall back to the slow heap iteration.
>
> R=mstarzinger@chromium.org
> BUG=v8:4132,v8:4052
> LOG=N
>
> Committed: https://crrev.com/cfe89a71a332ef9ed481c8210bc3ad6d2822034b
> Cr-Commit-Position: refs/heads/master@{#29296}

TBR=mstarzinger@chromium.org,yangguo@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4132,v8:4052

Review URL: https://codereview.chromium.org/1210393002

Cr-Commit-Position: refs/heads/master@{#29312}