[Bug lto/89358] [8 Regression] Combining -std=c++14 and -std=c++17 objects gives ODR warnings

[hubicka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89358

--- Comment #19 from Jan Hubicka <hubicka at gcc dot gnu.org> ---
I think backporting would be a good idea :) If you beat me on it even better.
Now I need to set up my trees in git...