[Bug c++/109291] type alias template rejects pack

[ncm at cantrip dot org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109291

--- Comment #2 from ncm at cantrip dot org ---
CWG 1430 is still marked Open, and is anyway only superficially
analogous. Here, there is no need for an alias to be encoded
into a type signature.