Roll src/third_party/re2/src/ 749d64c35..f620af75b (3 commits)

https://chromium.googlesource.com/external/github.com/google/re2.git/+log/749d64c35e09..f620af75bd69

$ git log 749d64c35..f620af75b --date=short --no-merges --format='%ad %ae %s'
2018-12-09 junyer Improve fuzzer coverage a little.
2018-11-22 junyer Make the NFA execution engine use Prog::EmptyFlags().
2018-11-06 junyer Improve the "MATCHING WITH SUBSTRING EXTRACTION" comment again.

Created with:
  roll-dep src/third_party/re2/src

R=mmoroz@chromium.org

Bug: 0
Change-Id: I3f8db84994270634e9e45d135b662feb3264686d
Reviewed-on: https://chromium-review.googlesource.com/c/1369764
Commit-Queue: Max Moroz <mmoroz@chromium.org>
Reviewed-by: Max Moroz <mmoroz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#615354}
1 file changed