[Bug c++/108390] ICE in fold_convert_loc, at fold-const.cc:2504 partial ordering between array types

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108390

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |ice-on-invalid-code
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2023-01-13
     Ever confirmed|0                           |1
           See Also|                            |https://gcc.gnu.org/bugzill
                   |                            |a/show_bug.cgi?id=79092

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I suspect the patch for PR79092 cahnged the behavior in GCC 8.

I don't see how this can't be ambiguous. It is odd that clang accepts it.

This C++20 testcase also causes the ICE and clang rejects it as ambiguous:

```
template<auto t> long f(int(*)[t], int(*)[t]);
template<int i> int f(int(*)[i], int(*)[i]);
int n = f<2>(0, 0);
```

So at least ICE on invalid.