Fix IfBuilder to use instruction factories. Add missing instruction factories.

Fix IfBuilder to use instruction factories. Add missing instruction factories.

This also makes the instruction constructors private and fixes
all uses of the public constructors to use the factory methods
instead.

R=svenpanne@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=16808

[Benedikt Meurer, 2013-09-18 13:08:40]

Hey Michael,
Here's the second part of the NumberToStringStub CL. It does some additional
cleanup, and also switches the IfBuilder to use instruction factories.
PTAL
-- Benedikt

[Sven Panne, 2013-09-19 06:44:44]

lgtm

[Benedikt Meurer, 2013-09-19 06:45:54]

Committed patchset #2 manually as r16808 (presubmit successful).

[mvstanton, 2013-09-19 07:55:38]

yep, looks good.