Revert of Use the LookupIterator in SetAccessor

Revert of Use the LookupIterator in SetAccessor (patchset #2 id:20001 of https://codereview.chromium.org/1178673003/)

Reason for revert:
Blocks reverting of https://codereview.chromium.org/1175973002

Original issue's description:
> Use the LookupIterator in SetAccessor
>
> BUG=v8:4137
> LOG=n
>
> Committed: https://crrev.com/f93276bfe093f576595c5dcac69cf8f9163915d9
> Cr-Commit-Position: refs/heads/master@{#28955}

TBR=jkummerow@chromium.org,verwaest@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4137
Committed: https://crrev.com/11dbd29de57b290ee8dac2a782a53f879beb416f
Cr-Commit-Position: refs/heads/master@{#28956}

[Igor Sheludko, 2015-06-11 17:19:38]

Created Revert of Use the LookupIterator in SetAccessor

[commit-bot: I haz the power, 2015-06-11 17:19:54]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1175323004/1

[commit-bot: I haz the power, 2015-06-11 17:20:02]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-06-11 17:20:20]

Patchset 1 (id:??) landed as
https://crrev.com/11dbd29de57b290ee8dac2a782a53f879beb416f
Cr-Commit-Position: refs/heads/master@{#28956}

[Toon Verwaest, 2015-06-11 20:20:22]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/1181813002/ by verwaest@chromium.org.

The reason for reverting is: Didn't break anything.