https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82922
--- Comment #3 from Martin Sebor <msebor at gcc dot gnu.org> --- Incremental patch for the testsuite: https://gcc.gnu.org/ml/gcc-patches/2018-01/msg00962.html Unfortunately it sounds like it might be too late to enable the option in GCC 8.
