MIPS: More OStreamsUse OStreams more often.

MIPS: More OStreamsUse OStreams more often.

Port r22232 (f837b91)

Original commit message:
This is a mostly mechanical CL (more than 90% Emacs macros and
query-replace-regexp) moving FILE*/StringStream*-based APIs to
OStream-based APIs. There are a few places where this had to stop,
otherwise the CL would be even bigger, but this can easily and
incrementally cleaned up later.

BUG=
R=palfia@homejinni.com

Committed: https://code.google.com/p/v8/source/detail?r=22250

[palfia, 2014-07-07 14:14:57]

LGTM

[kilvadyb, 2014-07-07 16:01:17]

Committed patchset #1 manually as r22250 (presubmit successful).