[Bug c++/86610] [8/9 Regression] non-const operator erroneously called in lambda in templated function

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86610

--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Smaller testcase from PR 87584

struct C
{
        int operator[](int)
        {
                return 0;
        }

        int operator[](int) const
        {
                return 1;
        }
};

template <typename T>
int f(T)
{
        C c;
        return [=] { return c[0]; }();
}

int main()
{
        return f(0);
}