https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68878
--- Comment #8 from Jan Hubicka <hubicka at gcc dot gnu.org> --- OK, the bug is caused by fact that new decl merging won't merge decls without symbol table entries. Devirtualization uses them and it means we lose a ctor. I have fix for the merging, but it seems to be a latent bug in ipa-cp or ipa-devirt I need to fix first - it should only cause a drop in number of devirtualizations, not a wrong code issue.
