[Bug c++/116015] ICE in replace_placeholders_r for simple default member initializer

[pieter.p.dev at outlook dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116015

--- Comment #3 from Pieter P <pieter.p.dev at outlook dot com> ---
A temporary workaround is to wrap the default value in an immediately invoked
lambda:

    struct Widget {
        int n = 5;
        Matrix A = [this] { return Matrix{{.rows = n}}; }();
    };