Multilibbing threaded supports

[Kean Johnston]

All,

Is it possible (or if not, desirable) to be able to multilib
around the top level --enable-threads option? On systems
where the threads library is separate from libc, being
able to do so makes sense, as you would only want a threaded
version of (say) libstdc++ if your app is threaded. Otherwise,
every application may potentially have to link against the
threads library, and that can cause a considerable overhead.

Advice / opinions welcome.

Kean