[Bug c++/126057] New: ICE on invalid structured binding

[kengusername at proton dot me via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126057

            Bug ID: 126057
           Summary: ICE on invalid structured binding
           Product: gcc
           Version: 15.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: kengusername at proton dot me
  Target Milestone: ---

This program fails to compile on gcc 15.1 with assertions

https://godbolt.org/z/b8e4oeobG

```
template<auto = 0> consteval auto foo() {
    static constexpr auto [a] = 0;
}

static_assert((foo(), 1));
```

This example behaves the same way on gcc 17 trunk.