Revert of Simplify and compact transitions storage

Revert of Simplify and compact transitions storage (patchset #4 id:80001 of https://codereview.chromium.org/980573002/)

Reason for revert:
x64 test failures

Original issue's description:
> Simplify and compact transitions storage
>
> Simple transitions are now stored in a map's "transitions" field (as a WeakCell wrapping the target map); full TransitionArrays are used when that's not sufficient.
> To encapsulate these storage format implementation details, functions for manipulating and querying transitions have been refactored to be static functions on the TransitionArray class, and take maps as inputs.
>
> Committed: https://crrev.com/45fbef7f2252fce10634931cb103ccc1fc95ae6a
> Cr-Commit-Position: refs/heads/master@{#27029}

TBR=verwaest@chromium.org,ulan@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Committed: https://crrev.com/948a973d458002cd3a66c14fb8635cb3256dc4b2
Cr-Commit-Position: refs/heads/master@{#27030}

[Jakob Kummerow, 2015-03-05 20:39:39]

Created Revert of Simplify and compact transitions storage

[commit-bot: I haz the power, 2015-03-05 20:41:35]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/982143002/1

[commit-bot: I haz the power, 2015-03-05 20:41:56]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-05 20:42:11]

Patchset 1 (id:??) landed as
https://crrev.com/948a973d458002cd3a66c14fb8635cb3256dc4b2
Cr-Commit-Position: refs/heads/master@{#27030}

[Jakob Kummerow, 2015-03-06 12:33:48]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/988703002/ by jkummerow@chromium.org.

The reason for reverting is: reland.