message: fuzz: libc++ clocks don't like nanos.
  This was breaking ClusterFuzz.
diff: @@ -36,13 +36,9 @@ inline test::fuzz::Headers toHeaders(const Http::HeaderMap& headers) {
  inline TestRequestInfo fromRequestInfo(const test::fuzz::RequestInfo& request_info) {
  TestRequestInfo test_request_info;
  test_request_info.metadata_ = request_info.dynamic_metadata();
  -#ifdef __APPLE__
  - // Clocks don't track at nanosecond on OS X.
  + // libc++ clocks don't track at nanosecond on OS X.
  test_request_info.start_time_ =
  SystemTime(std::chrono::microseconds(request_info.start_time() / 1000));
  -#else
  - test_request_info.start_time_ = SystemTime(std::chrono::nanoseconds(request_info.start_time()));
  -#endif
  if (request_info.has_response_code()) {
  test_request_info.response_code_ = request_info.response_code().value();
  }
  