https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78056
--- Comment #9 from David Edelsohn <dje at gcc dot gnu.org> --- Any *one* of the BU_P9V_AV_P builtins will cause the failure. If those builtins are commented out of rs6000-builtins.def (with the appropriate changes to rs6000-c.c), bootstrap will succeed.
