[Bug c++/86648] [9 Regression] ICE on class template argument deduction

[aoliva at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86648

--- Comment #6 from Alexandre Oliva <aoliva at gcc dot gnu.org> ---
https://gcc.gnu.org/ml/gcc-patches/2018-12/msg01740.html