Revert of [ic] Use validity cells to protect keyed element stores against object's prototype chain modificati… (patchset #2 id:40001 of https://codereview.chromium.org/2534613002/ )

Reason for revert:
Layout test crashes:
https://build.chromium.org/p/client.v8.fyi/builders/V8-Blink%20Linux%2064/builds/11691

Original issue's description:
> [ic] Use validity cells to protect keyed element stores against object's prototype chain modifications.
>
> ... instead of clearing of all the KeyedStoreICs which didn't always work.
>
> BUG=chromium:662907, v8:5561
> TBR=verwaest@chromium.org, bmeurer@chromium.org
>
> Committed: https://crrev.com/a39522f44f7e0be4686831688917e9675255dcaf
> Cr-Commit-Position: refs/heads/master@{#41332}

TBR=jkummerow@chromium.org,ishell@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:662907, v8:5561

Review-Url: https://codereview.chromium.org/2538693002
Cr-Commit-Position: refs/heads/master@{#41337}