https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71445
--- Comment #11 from Jakub Jelinek <jakub at gcc dot gnu.org> --- True; on the other side, at least for backports we need some other solution, because the symbol versioning stuff can't be backported to GCC 6.2 or 5.5 and people will surely want to be able to compile those GCCs against more recent glibcs.
