The currently included version of mesa does not include a 32bit dri library for radeonsi, what makes running 32bit opengl applications impossible on such a card when using the open source drivers without unmasking all the multilib stuff.
Expected result: a working version of radeonsi_dri.so should be installed in /usr/lib32/mesa
Obtained result: the file is missing
Suggested solution: Either keep this disappointing situation until multilib is fully ready, or build a mesa version with radeonsi support.
20140608 version still doesn't have a radeonsi driver
The emul-linux-x86 packages have been removed.