While I feel the terminology "multilib" is not accurate (i.e.Having lib, lib32, it's confusing GNU toolchain's multilib) for having lib and lib64,... it's better to be friendly to such use case.
IIUC, here are some info:
- they (will) use <host_alias>-gpgrt-config script
- in configure, CC is cc or gcc with no <host_alias>- prefix
http://www.pilotlogic.com/sitejoom/index.php/wiki?id=398
(I feel the terminology "multilib" is not that accurate (i.e., it's confusing GNU toolchain's multilib) )