Every place where AllocationMemento is initialized with an

Every place where AllocationMemento is initialized with an 
AllocationSite is now checked to be sure a valid Site goes in. 
This is temporary code to diagnose chromium bug 284577.

BUG=
R=mstarzinger@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=16705

[mvstanton, 2013-09-12 15:01:33]

Hi Michael, here is the CL that checks each location where we SET an
AllocationSite into a Memento. I'll be sure perf impact isn't too severe before
checking in. The CL relies on the other fixes you are looking at today from me,
thx again!
--Michael

[Michael Starzinger, 2013-09-12 17:09:46]

LGTM.

[mvstanton, 2013-09-13 08:13:26]

Committed patchset #1 manually as r16705 (presubmit successful).