[Bug c++/67632] explicit instantiation omits copy constructor and others

[jlink at drw dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67632

--- Comment #3 from Joseph Link <jlink at drw dot com> ---
Yeah, watch out for the copy constructor that takes an allocator.  That one's
there.  The compiler generated one is not.