Transitions from DOUBLE to FAST were not checking for allocation site info.

Transitions from DOUBLE to FAST were not checking for allocation site info.
This creates a confusing result. It's better to let allocation sites
transition to their end state than artificially stop tracking at the
double/fast boundary.

BUG=
R=verwaest@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=16820

[mvstanton, 2013-08-26 14:18:04]

Hi Toon,
If you get a chance tomorrow or so to have a quick look. I believe this CL came
out of a debugging session we had some weeks ago. The allocation site info is
unnecessarily restrictive in accepting feedback for transitions from double to
fast for array literals that started with smi elements kind.
Thanks,
--michael

[Toon Verwaest, 2013-09-18 15:04:36]

lgtm

[mvstanton, 2013-09-19 09:48:59]

Committed patchset #2 manually as r16820 (presubmit successful).