That's really a total madness from Ubuntu's folks... Breaking a standard (UNIX files layout) that existed for decades !
Anyway, all you have to do in this case, is to create a symbolic link for each /lib and /usr/lib, like so:
And any third party 32 bits binary should work again just fine...
They are not new versions (same *major* number, which is what counts). So there is no need to create a symbolic link for each of them (there should already be a link from libXext.so.6 to libXext.so.6.4.0 in your /usr/lib32 directory, for example)...