[Bug target/79671] [7 Regression] mapnik miscompilation on armv7hl since r235622

["jakub at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79671

--- Comment #16 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
With -Wsystem-headers there are various warnings, e.g.
/usr/include/boost/function/function_template.hpp:572:11: warning: placement
new constructing an object of type
‘boost::spirit::qi::detail::parser_binder<boost::spirit::qi::plus<boost::spirit::qi::difference<boost::spirit::qi::char_class<boost::spirit::tag::char_code<boost::spirit::tag::char_,
boost::spirit::char_encoding::standard_wide> >,
boost::spirit::qi::literal_char<boost::spirit::char_encoding::standard, true,
false> > >, mpl_::bool_<true> >’ and size ‘2’ in a region of type ‘char’ and
size ‘1’ [-Wplacement-new=]
           new (reinterpret_cast<void*>(&functor.data)) FunctionObj(f);
           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/boost/function/function_base.hpp:308:13: warning: placement new
constructing an object of type
‘boost::detail::function::functor_manager_common<boost::spirit::qi::detail::parser_binder<boost::spirit::qi::plus<boost::spirit::qi::difference<boost::spirit::qi::char_class<boost::spirit::tag::char_code<boost::spirit::tag::char_,
boost::spirit::char_encoding::standard_wide> >,
boost::spirit::qi::literal_char<boost::spirit::char_encoding::standard, true,
false> > >, mpl_::bool_<true> > >::functor_type {aka
boost::spirit::qi::detail::parser_binder<boost::spirit::qi::plus<boost::spirit::qi::difference<boost::spirit::qi::char_class<boost::spirit::tag::char_code<boost::spirit::tag::char_,
boost::spirit::char_encoding::standard_wide> >,
boost::spirit::qi::literal_char<boost::spirit::char_encoding::standard, true,
false> > >, mpl_::bool_<true> >}’ and size ‘2’ in a region of type ‘char’ and
size ‘1’ [-Wplacement-new=]
             new (reinterpret_cast<void*>(&out_buffer.data))
functor_type(*in_functor);
            
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
etc.