[Bug ipa/61659] [4.9 Regression] Extra undefined symbol because of devirtualization

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61659

--- Comment #28 from Jason Merrill <jason at gcc dot gnu.org> ---
(In reply to Markus Trippelsdorf from comment #27)
> Possible fix:

Applied to trunk, thanks.