PPC: Use Cells to check prototype chain validity (disabled by default).

PPC: Use Cells to check prototype chain validity (disabled by default).

Port 0179ec57975c5063bbecd98e11cdda77ddad8996

Original commit message:
The cells are stored on prototypes (in their map's PrototypeInfo). When a prototype object changes its map, then both its own validity cell and those of all "downstream" prototypes are invalidated; handlers for a given receiver embed the currently valid cell for that receiver's prototype during their compilation and check it on execution.

R=michael_dawson@ca.ibm.com, dstence@us.ibm.com
BUG=

Committed: https://crrev.com/0dc5fd7080daee1925aed292108ce8ecc8e464c2
Cr-Commit-Position: refs/heads/master@{#27849}

[MTBrandyberry, 2015-04-15 14:10:41]

Fix PPC build break.

[michael_dawson, 2015-04-15 14:13:34]

On 2015/04/15 14:10:41, mtbrandyberry wrote:
> Fix PPC build break.

lgtm.

[MTBrandyberry, 2015-04-15 14:16:11]

The CQ bit was checked by mbrandy@us.ibm.com

[commit-bot: I haz the power, 2015-04-15 14:16:16]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1091563002/20001

[commit-bot: I haz the power, 2015-04-15 14:40:03]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-04-15 14:40:10]

Patchset 2 (id:??) landed as
https://crrev.com/0dc5fd7080daee1925aed292108ce8ecc8e464c2
Cr-Commit-Position: refs/heads/master@{#27849}