"the structure of efficient software that can predict a human mind is itself a human mind." - I doubt that. Why do you think this is the case? I think there are already many examples where simple statistical models (e.g. linear regression) can do a better job of predicting some things about a human than an expert human can.

Also, although I don't think there is "one true definition" of AGI, I think there is a meaningful one which is not particularly anthropocentric, see Chapter 1 of Shane Legg's thesis: http://www.vetta.org/documents/Machine_Super_Intelligence.pdf.

"Intelligence measures an agent’s ability to achieve goals in a wide range of environments."

So, arguably that should include environments with humans in them. But to succeed, an AI would not necessarily have to predict or model human minds; it could instead, e.g. kill all humans, and/or create safeguards that would prevent its own destruction by any existing technology.