There is no such thing as "gcc system".
Linux distributions by default comes without any kind of compiler but the runtime libraries are there, the only problem was the libstdc++ library, the distros deside witch one to put, however gcc3 and gcc4 both can use the new libstdc++ library so it doesn't matter, the other libraries that one simple shared library as podbot_mm or other apps that is not using third party libraries (gtk or qt for example) will work without problem not depending by the compiler that is used.