[Bug c++/115775] User-defined deduction guide ignored for alias template if the alias passes on a template template parameter to the aliased class template

[s.murthy at outlook dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115775

--- Comment #3 from Sean Murthy <s.murthy at outlook dot com> ---
I notice the repro has an unnecessary explicit specifier for guide 2. That
guide should be:

//guide 2
template <bool B, std::signed_integral SI>
C(SI) -> C<B, std::make_unsigned_t<SI>>;