Also, I've tried to replace parser with a modern one. Claude succeeds in generating Java 8 parsers with various parser generators/parser combinators but fails to resolve extremely tight coupling.
setting copyright issues aside, javac is a pretty clean textual-input-output program, and It can probably be reduced to a single thread variant
from the old parser ast -> to json -> to new ast representation (that is basically again copy of the old one) -> to some new incomplete bytecode generation
im sure there is some good explanation, but....why?! :)
In the end I've just reanimated the original parser generator and progressed to full Java 7 syntactically (-att5 branch), but there are some major obstacles with bytecode.