graphics/libetonyek01: unbreak build on 9.x

In file included from conftest.cpp:43:
In file included from /usr/local/include/boost/spirit/include/phoenix.hpp:13:
In file included from /usr/local/include/boost/spirit/home/phoenix.hpp:10:
In file included from /usr/local/include/boost/spirit/home/phoenix/algorithm.hpp:10:
In file included from /usr/local/include/boost/spirit/home/phoenix/stl/algorithm/iteration.hpp:20:
In file included from /usr/local/include/boost/spirit/home/phoenix/function/function.hpp:10:
In file included from /usr/local/include/boost/spirit/home/phoenix/core/compose.hpp:16:
In file included from /usr/local/include/boost/spirit/home/phoenix/core/composite.hpp:10:
In file included from /usr/local/include/boost/spirit/home/phoenix/core/actor.hpp:18:
In file included from /usr/local/include/boost/spirit/home/phoenix/core/basic_environment.hpp:18:
In file included from /usr/local/include/boost/fusion/include/mpl.hpp:11:
In file included from /usr/local/include/boost/fusion/mpl.hpp:17:
In file included from /usr/local/include/boost/fusion/mpl/clear.hpp:12:
In file included from /usr/local/include/boost/fusion/mpl/detail/clear.hpp:12:
In file included from /usr/local/include/boost/fusion/container/map/map_fwd.hpp:24:
/usr/local/include/boost/fusion/container/map/detail/map_impl.hpp:76:23: error: no template named 'forward' in namespace 'std'; did you mean 'advance_detail::forward'?

: rest_type(std::forward<rest_type>(*static_cast<rest_type*>(this)))
            ^~~~~~~~~~~~
            advance_detail::forward

/usr/local/include/boost/fusion/iterator/detail/advance.hpp:37:12: note: 'advance_detail::forward' declared here

struct forward
       ^

In file included from /usr/local/include/glm/detail/func_trigonometric.hpp:205:0,

from /usr/local/include/glm/trigonometric.hpp:35,
from /usr/local/include/glm/glm.hpp:110,
from conftest.cpp:49:

/usr/local/include/glm/detail/func_trigonometric.inl:166:14: error: 'std::asinh' has not been declared

using std::asinh;
           ^

In file included from /usr/local/include/glm/detail/func_common.hpp:455:0,

from /usr/local/include/glm/common.hpp:35,
from /usr/local/include/glm/glm.hpp:112,
from conftest.cpp:49:

/usr/local/include/glm/detail/func_common.inl:229:16: error: 'std::trunc' has not been declared

using ::std::trunc;
             ^

/usr/local/include/glm/detail/func_common.inl:248:16: error: 'std::round' has not been declared

using ::std::round;
             ^

Reported by: pkg-fallout, Robert Backhaus