Revert of Reland "Keep a canonical list of shared function infos." (patchset #3 id:40001 of https://codereview.chromium.org/1211453002/)

Reason for revert:
proxies test failing https://chromegw.corp.google.com/i/client.v8/builders/V8%20Linux64%20GC%20Stress%20-%20custom%20snapshot/builds/903/steps/Mjsunit/logs/proxies

Original issue's description:
> Reland "Keep a canonical list of shared function infos."
>
> This reverts commit 3164aa74.
>
> Committed: https://crrev.com/cacb646d80daa429f6915824a741f595db7d5044
> Cr-Commit-Position: refs/heads/master@{#29282}

TBR=adamk@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/1206263002

Cr-Commit-Position: refs/heads/master@{#29285}