[Bug c++/59165] gcc looks up begin(), end() for for-range loops for ints in namespace std

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59165

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> ---
I think I remember the rationale now: std::begin and std::end only work if
c.begin() and c.end() xist, in which case range-based for will use those
members directly anyway.