[Bug c++/58377] spurious "may be unused" warning with -Og

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58377

--- Comment #1 from Paolo Carlini <paolo.carlini at oracle dot com> ---
I can't reproduce this issue with stock FSF GCCs. In any case, it doesn't look
like a C++ front-end issue, I would recommend preparing an equivalent pure C
program for the convenience of middle-end people (changing pop to be free
standing functions and little more should be enough). Often I do that kind of
work but I can't reproduce the issue in the first place in this case.