Express LoadIC extra ic state with LoadIC::State

Express LoadIC extra ic state with LoadIC::State

Soon we will create code stubs that need to match LoadIC state. It's easier to
express if the state is encapsulated in a single class rather than multiple bit
fields.

R=verwaest@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=22559

[mvstanton, 2014-07-23 11:56:46]

HI Toon,
Here is the change we discussed. I will revisit eliminating ContextualMode
later. thx,
--Michael

[Toon Verwaest, 2014-07-23 12:17:50]

lgtm

[mvstanton, 2014-07-23 12:24:17]

Committed patchset #2 manually as r22559.