[Bug c++/85147] [6/7/8 Regression] ICE with invalid variadic template-template parameter

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85147

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 43812
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=43812&action=edit
gcc8-pr85147.patch

Untested fix.