Revert of [heap] Unify the immortal immovable root detection mechanism.

Revert of [heap] Unify the immortal immovable root detection mechanism. (patchset #3 id:40001 of https://codereview.chromium.org/1178853002/)

Reason for revert:
[Sheriff] tsan failures:
http://build.chromium.org/p/client.v8/builders/V8%20Linux64%20TSAN/builds/4240

Original issue's description:
> [heap] Unify the immortal immovable root detection mechanism.
>
> Uniformly use the Heap::GetRootListIndex() and
> Heap::RootIsImmortalImmovable() methods to detect immortal immovable
> roots in the optimizing compilers.
>
> R=jarin@chromium.org
>
> Committed: https://crrev.com/84e83da99a72edc169367bf88588b1a2f10c2e08
> Cr-Commit-Position: refs/heads/master@{#28933}

TBR=jarin@chromium.org,bmeurer@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Committed: https://crrev.com/af83ab69b9568c005b5feca8b272a082b7da7f1d
Cr-Commit-Position: refs/heads/master@{#28934}

[Michael Achenbach, 2015-06-11 10:49:10]

Created Revert of [heap] Unify the immortal immovable root detection mechanism.

[commit-bot: I haz the power, 2015-06-11 10:49:25]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1178083003/1

[commit-bot: I haz the power, 2015-06-11 10:49:39]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-06-11 10:49:51]

Patchset 1 (id:??) landed as
https://crrev.com/af83ab69b9568c005b5feca8b272a082b7da7f1d
Cr-Commit-Position: refs/heads/master@{#28934}