[Bug c++/126124] ICE on packed structured binding through statement expression

[feedabl3 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126124

feedable <feedabl3 at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |feedabl3 at gmail dot com

--- Comment #1 from feedable <feedabl3 at gmail dot com> ---
Same is reproducible with IILE:
https://godbolt.org/z/sdxanhz7M

```
template<auto = 0> consteval auto foo() {
    int arr[] {};
    ( [&]{auto [...p] = arr; p;}(), ...);
}

static_assert(foo());
```

We should probably check that the packs to be expanded are not themselves part
of the pattern.