Revert of [turbofan] Restore basic write barrier elimination. (patchset #2 id:20001 of https://codereview.chromium.org/1938993002/ )

Reason for revert:
Breaks WBs that should be there ;)

https://uberchromegw.corp.google.com/i/client.v8/builders/V8%20Linux%20-%20gc%20stress/builds/3305

Will open repro bug asap.

Original issue's description:
> [turbofan] Restore basic write barrier elimination.
>
> Restore the basic write barrier elimination that we used to run as part
> of the simplified lowering phase (in ChangeLowering actually) before, by
> moving the write barrier computation to SimplifiedLowering where we can
> still look at types and consider the heap/isolate, and just update the
> WriteBarrierKind in the FieldAccess/ElementAccess that we later use when
> lowering to a machine Load/Store.
>
> CQ_INCLUDE_TRYBOTS=tryserver.v8:v8_linux64_tsan_rel
> R=mstarzinger@chromium.org
> BUG=v8:4969,chromium:608636
> LOG=n
>
> Committed: https://crrev.com/7dcb6ad379fbacbc8bdc8e11a6e50d680ffa3f62
> Cr-Commit-Position: refs/heads/master@{#35969}

TBR=mstarzinger@chromium.org,bmeurer@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4969,chromium:608636

Review-Url: https://codereview.chromium.org/1943743003
Cr-Commit-Position: refs/heads/master@{#35983}