Revert of [fullcodegen] Refactor code that calls store ICs. (patchset #1 id:20001 of https://codereview.chromium.org/2363513003/ )

Reason for revert:
race suspect:
https://build.chromium.org/p/client.v8/builders/V8%20Linux64%20TSAN/builds/11893

Original issue's description:
> [fullcodegen] Refactor code that calls store ICs.
>
> Make FCG::CallStoreIC() load slot and name and make FCG::CallKeyedStoreIC() load
> slot according to store IC calling convention (StoreDescriptor).
>
> BUG=v8:5407
>
> Committed: https://crrev.com/12918397b4af7b2bede8b29e1e9b1940d5d5ad3b
> Cr-Commit-Position: refs/heads/master@{#39679}

TBR=mvstanton@chromium.org,ishell@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:5407

Review-Url: https://codereview.chromium.org/2363123002
Cr-Commit-Position: refs/heads/master@{#39682}