Track number of generic ICs per function

Track number of generic ICs per function

and use it to disable optimization if too many ICs are generic.

R=verwaest@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=22887

[Jakob Kummerow, 2014-08-04 16:00:30]

PTAL.

[Toon Verwaest, 2014-08-04 16:47:18]

lgtm

[Vyacheslav Egorov (Google), 2014-08-04 17:59:44]

DBC:

I have seen IC based heuristics misfire for code that is high on direct function
calls but low on ICs.

e.g. see http://jsperf.com/standalone-vs-method/2 where OSR never hits the loop
because we use amount of initialized ICs to drive optimization decisions.

[Toon Verwaest, 2014-08-04 18:13:31]

Surely these IC-based heuristics are a temporary solution until we have more
stable feedback.

[Jakob Kummerow, 2014-08-05 17:06:11]

Committed patchset #1 manually as r22887 (presubmit successful).