[Bug libstdc++/60176] [C++11] void return value in std::list<>::insert() c++1 should be an iterator

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60176

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Our std::list needs work to conform to C++11