PR c++/5645
        PR c++/11159
        * class.c (type_has_user_nondefault_constructor): New fn.
        * cp-tree.h: Declare it.
        * init.c (emit_mem_initializers): Use it for -W warning about
        missing base initializer.

Co-Authored-By: Jason Merrill <jason@redhat.com>

From-SVN: r132324