[turbofan] Implement the implicit ToObject for property access.

[turbofan] Implement the implicit ToObject for property access.

Drive-by-fix: Move IC::GetRootConstructor to Map::GetConstructorFunction,
so we can use that in the ICs, Crankshaft and Turbofan.

R=jarin@chromium.org
BUG=v8:4470
LOG=n

Committed: https://crrev.com/44f4c1d66a1476f2a2f6101616525a32f113eef3
Cr-Commit-Position: refs/heads/master@{#31577}

[Benedikt Meurer, 2015-10-26 14:59:14]

Hey Jaro,

Does the automagic ToObject in GetV, somewhat unified with the ICs and
Crankshaft.
Please take a look.

Thanks,
Benedikt

[Jarin, 2015-10-26 15:21:43]

lgtm

[Benedikt Meurer, 2015-10-26 15:32:55]

The CQ bit was checked by bmeurer@chromium.org

[commit-bot: I haz the power, 2015-10-26 15:33:07]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1416493007/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1416493007/1

[commit-bot: I haz the power, 2015-10-26 15:55:42]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-10-26 15:55:57]

Patchset 1 (id:??) landed as
https://crrev.com/44f4c1d66a1476f2a2f6101616525a32f113eef3
Cr-Commit-Position: refs/heads/master@{#31577}