Replace RE2 import with a dependency

third_party/re2/util/test.cc

-// Copyright 2009 The RE2 Authors.  All Rights Reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-#include <stdio.h>
-#ifndef _WIN32
-#include <sys/resource.h>
-#endif
-#include "util/test.h"
-
-DEFINE_string(test_tmpdir, "/var/tmp", "temp directory");
-
-struct Test {
-  void (*fn)(void);
-  const char *name;
-};
-
-static Test tests[10000];
-static int ntests;
-
-void RegisterTest(void (*fn)(void), const char *name) {
-  tests[ntests].fn = fn;
-  tests[ntests++].name = name;
-}
-
-int main(int argc, char **argv) {
-  for (int i = 0; i < ntests; i++) {
-    printf("%s\n", tests[i].name);
-    tests[i].fn();
-  }
-  printf("PASS\n");
-  return 0;
-}