Remove all uses of field-tracking flags that do not make decisions but are subject to existing info…

Remove all uses of field-tracking flags that do not make decisions but are subject to existing information.

BUG=
R=ishell@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=19650

[Toon Verwaest, 2014-02-20 16:24:14]

PTAL

[Igor Sheludko, 2014-02-25 16:30:55]

lgtm with a nit: I think you can also remove FLAG_track_double_fields usages
from FullCodeGenerator::VisitObjectLiteral() (all platforms).

[Toon Verwaest, 2014-03-04 12:48:33]

Committed patchset #4 manually as r19650 (presubmit successful).