[Bug c++/57557] can't reference static const int member with optimizations on

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57557

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Doh, sorry, I completely misread the test!

It's still undefined behaviour though, obj is uninitialized and you're missing
a return from A::foo