Reduce diff to upstream re2 a bit.

Reduce diff to upstream re2 a bit.

- this-null.patch has landed upstream, remove the patch file
- msvs2013 has a stdint.h, so remove our downstream stdint.h copy in re2
- msvs2013 has va_copy, so don't define it locally

BUG=414049
NOTRY=true

Committed: https://crrev.com/122432e01f12f263184f77cb27a2b49f7c5d04be
Cr-Commit-Position: refs/heads/master@{#294836}

[Nico, 2014-09-13 22:34:07]

thakis@chromium.org changed reviewers:
+ scottmg@chromium.org

[scottmg, 2014-09-15 16:29:17]

lgtm

[Nico, 2014-09-15 16:31:10]

The CQ bit was checked by thakis@chromium.org

[commit-bot: I haz the power, 2014-09-15 16:32:04]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patchset/564293002/20001

[commit-bot: I haz the power, 2014-09-15 16:39:13]

Committed patchset #2 (id:20001) as aba8636976f27e3d2f332ab3e381c408482843d9

[commit-bot: I haz the power, 2014-09-15 16:46:40]

Patchset 2 (id:??) landed as
https://crrev.com/122432e01f12f263184f77cb27a2b49f7c5d04be
Cr-Commit-Position: refs/heads/master@{#294836}