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

Port 0179ec57

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=

Review URL: https://codereview.chromium.org/1091563002

Cr-Commit-Position: refs/heads/master@{#27849}