[Bug c++/108099] ICE with type alias with `signed __int128_t`

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108099

--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I forgot to mention we do reject:
```
typedef signed __int128_t t;
```
already too.