Roll src/third_party/re2/src/ 209319c1b..787495f0b (23 commits)

https://chromium.googlesource.com/external/github.com/google/re2.git/+log/209319c1bf57..787495f0ba2e

$ git log 209319c1b..787495f0b --date=short --no-merges --format='%ad %ae %s'
2020-05-22 junyer Use CMAKE_CXX_STANDARD now that we can.
2020-05-22 junyer Make "front and back" prefix accel work with MSVC.
2020-05-22 junyer Rename to Regexp::RequiredPrefixForAccel().
2020-05-22 junyer Add a basic test for prefix accel.
2020-05-20 junyer Implement "front and back" prefix accel.
2020-05-19 junyer Generalise from "first byte" to "prefix accel".
2020-05-19 junyer have_first_byte now implies run_forward.
2020-05-19 junyer Tidy up the code around the memchr(3) calls.
2020-05-17 junyer Remove a pointer chase from Regexp::Walker<>.
2020-05-17 junyer Tidy up the code for NFA threads a bit more.
2020-05-17 junyer Argh. I overlooked the constructor and destructor.
2020-05-17 junyer Undo use of PODArray<> for NFA threads.
2020-05-17 junyer Use PODArray<> in a few more places.
2020-05-16 junyer Separate build/install for libre2.a and libre2.so.
2020-05-16 junyer Refine a preprocessor check for MSVC.
2020-05-15 junyer Compute first byte for forward Progs only.
2020-05-11 junyer Don't dereference params->start unconditionally.
2020-05-11 junyer Compute first_byte using the Regexp, not the Prog.
2020-05-11 junyer Implement Regexp::RequiredPrefixUnanchored().
2020-05-11 junyer Refactor Regexp::RequiredPrefix().
2020-05-10 junyer Lower the memory budget in TestCompile.InsufficientMemory.
2020-05-05 junyer Remove first_byte from StartInfo and simplify accordingly.
2020-05-02 junyer `^' is a caret, not a carat.

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

R=thakis@chromium.org
CC=mmoroz@chromium.org

Change-Id: I119116e108b7b58a4fd00b766f33483e31b2ae64
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2218493
Commit-Queue: Paul Wankadia <junyer@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#772307}

DEPS

@@ -1317,7 +1317,7 @@ deps = {
   },
 
   'src/third_party/re2/src':
-    Var('chromium_git') + '/external/github.com/google/re2.git' + '@' + '209319c1bf57098455547c5779659614e62f3f05',
+    Var('chromium_git') + '/external/github.com/google/re2.git' + '@' + '787495f0ba2e76dcadb21db84455ea0e2ce15beb',
 
   'src/third_party/r8': {
       'packages': [