Method get_lines

oneflow/extension/stack/stacktrace.h:3657–3660

  }

  lines_t get_lines(unsigned line_start, unsigned line_count) {
    lines_t lines;
    return get_lines(line_start, line_count, lines);
  }

  // there is no find_if_not in C++98, lets do something crappy to
  // workaround.