cmake HAS_VISIBILITY examples

kevin2431/Traj-LO thirdparty/ros/console_bridge/CMakeLists.txt :24 

check_c_compiler_flag(-fvisibility=hidden HAS_VISIBILITY)

luigifreda/slamplay thirdparty/ros/console_bridge/CMakeLists.txt :24 

check_c_compiler_flag(-fvisibility=hidden HAS_VISIBILITY)