src: remove classes and nodes related to the old syntax

Signed-off-by: Jean Privat <jean@pryen.org>
nitx: remove unused methods `AAttrPropdef::*_accessor`

Signed-off-by: Jean Privat <jean@pryen.org>
nitpreyty: remove the oldstyle syntax, there is still some fixme to fix

Signed-off-by: Jean Privat <jean@pryen.org>
tests: update some AST-related sav/*.res files for tools

Signed-off-by: Jean Privat <jean@pryen.org>