[Bug c++/113141] New: ICE on conversion to reference in aggregate initialization

["de34 at live dot cn" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113141

            Bug ID: 113141
           Summary: ICE on conversion to reference in aggregate
                    initialization
           Product: gcc
           Version: 13.2.1
            Status: UNCONFIRMED
          Keywords: ice-checking, ice-on-invalid-code
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: de34 at live dot cn
  Target Milestone: ---

The following program triggers ICE since GCC 13
(https://godbolt.org/z/PaqWsG9s6):

```
int global_x{};

struct ConvToRef {
    operator int&() { return global_x; }
};

struct Foo { int& r; };

int main()
{
    Foo bar{ { ConvToRef{} } };
}
```

Clang considers this ill-formed and emits "non-const lvalue reference to type
'int' cannot bind to an initializer list temporary".

If the type of r is changed to const int&, the program correctly compiles with
GCC.