Any Lisp or Scheme. Because of the cited features. Homoiconicity only helps with macros.
I should have mentioned Prolog also, because this is even better for compilers. You state the rules, and the system comes up with the optimal transformation by itself. Trees are natural as in Lisp. But unfortunately Prolog is not popular enough, and you rarely see an open source Prolog compiler. Ocaml took that niche, but prolog would be far better.
Nothing comes close to efficient tree matching or list processing, esp with its macros.