emul-linux-x86-opengl has been fully ported to gx86-multilib, so packages should no longer depend on it (instead depending on the specific libraries they require) when multilib is in use.
Never got around to working on this, and there's now a full list of emul-linux-x86 dependencies at <https://wiki.gentoo.org/wiki/Multilib_porting_status#Dependency_update_status>, so closing.