[Bug c++/57694] [c++11] constexpr constructor does not work with const address of own member

[paolo.carlini at oracle dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57694

--- Comment #2 from Paolo Carlini <paolo.carlini at oracle dot com> ---
This is fixed for 5.0 in r216750. I'm adding the testcase and closing the bug.