I ran into an issue going 100% multilib. I was advised that with a video card as as poor as the one built into my laptop, I should install llvm and recompile mesa with --with-llvm, because my video card has no vertex shader (Whatever that is, but guys thought it was important). This took me off all beaten tracks with mesa, and I compiled my own (Slackware)package. a 32 bit version refused to compile, and I gave up.
I have stuck in the libs from the slackware-current mesa-7.10.2 package. ldd can find all the libs for libGL.so.1, googleearth-bin has all it's libs in 32 bit. I'm not sure I am 100% multilib, but I'm fairly close. I did not stick in 32 bit libs for stuff not present or used on my system.