CXX-1304 CXX-1304 Document std::experimental polyfill as unsupported
CXX-1304 CXX-1304 Document std::experimental polyfill as unsupported

mongodb/mongo-cxx-driver,acmorrow/mongo-cxx-driver,acmorrow/mongo-cxx-driver,xdg/mongo-cxx-driver,mongodb/mongo-cxx-driver,acmorrow/mongo-cxx-driver,mongodb/mongo-cxx-driver,xdg/mongo-cxx-driver,xdg/mongo-cxx-driver,acmorrow/mongo-cxx-driver,mongodb/mongo-cxx-driver,xdg/mongo-cxx-driver