I'm not sure if this is what you're after, since it's not really in book form, but I've learned a lot about advanced language implementation from reading the Rust RFCs [1], especially those relating to MIR. Between the discussion on each PR and the resulting implementation in the actual compiler, it makes some very complicated subjects more relatable than they normally would be. I'm really grateful that so much of Rust's development happens in such an open fashion.
[1] https://github.com/rust-lang/rfcs