[Bug c++/106863] ICE in write_template_arg_literal, at cp/mangle.cc:3678 since r12-4782-geca767aa51d1f696

[jehova at existiert dot net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106863

--- Comment #2 from jehova at existiert dot net ---
I'm not sure if 'ice-on-valid-code' is appropriate here, since the example code
is *not* valid.
It is if 'void{}' is replaced by 'void()' (which is perfectly accepted by GCC).