Adding Google benchmarking library.

third_party/google_benchmark/cmake/std_regex.cpp

Index: third_party/google_benchmark/cmake/std_regex.cpp
diff --git a/third_party/google_benchmark/cmake/std_regex.cpp b/third_party/google_benchmark/cmake/std_regex.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..696f2a26bce02fbcec39ee1786c151400290b31e
--- /dev/null
+++ b/third_party/google_benchmark/cmake/std_regex.cpp
@@ -0,0 +1,10 @@
+#include <regex>
+#include <string>
+int main() {
+  const std::string str = "test0159";
+  std::regex re;
+  re = std::regex("^[a-z]+[0-9]+$",
+       std::regex_constants::extended | std::regex_constants::nosubs);
+  return std::regex_search(str, re) ? 0 : -1;
+}
+