AVR toolchain update

I've been delaying this update for quite a while. At the moment I've
got a working binutils-avr, and I'm trying to make gcc work. I'm still
not on the 4.4 train, which IIRC introduced the gcc-libs package. I
have to admit that the gcc-libs role is not really clear to me, and
I'm not sure I need an AVR-compiled version, but my gcc-avr build
still fails and I don't know why, so I have no way to check. Can
someone who knows more than me shed some light on this?

Thanks,
Corrado