Subzero: Improve malloc/free behavior.

Subzero: Improve malloc/free behavior.

Use a bigger block size in the bump-pointer allocators, since we
basically know up front that we'll need lots of memory.  The 1MB value
(versus the default of 4KB) was chosen somewhat arbitrarily, and
succeeds in pretty much removing bump-pointer related mallocs from the
profile.

Pre-reserve the a priori known number of edges in getTerminatorEdges()
to avoid vector resizing.

BUG= none
R=kschimpf@google.com

Committed: https://gerrit.chromium.org/gerrit/gitweb?p=native_client/pnacl-subzero.git;a=commit;h=9d801a0123d352f3e94937954883ec5acaa842dd

[Jim Stichnoth, 2014-11-26 21:34:31]

stichnot@chromium.org changed reviewers:
+ jvoung@chromium.org, kschimpf@chromium.org

[Jim Stichnoth, 2014-11-26 21:57:49]

Forgot to say that this appears to give 1-2% improvement in translation time.

[Karl, 2014-11-26 22:04:56]

kschimpf@google.com changed reviewers:
+ kschimpf@google.com

[Karl, 2014-11-26 22:04:56]

lgtm

[Jim Stichnoth, 2014-11-26 22:11:57]

Committed patchset #1 (id:1) manually as
9d801a0123d352f3e94937954883ec5acaa842dd (presubmit successful).