Publish syn.json in some crate

[programmerjake]

I'm currently trying to write a processor for syn AST (implementing #[cfg] handling for an attribute macro for fn items), but can't use any of Visit/VisitMut/Fold since I need a custom output type. I'm aware of syn-codegen but afaict neither syn nor syn-codegen as published on crates.io actually include syn.json, and I don't want to require internet access when building my code so can't just download syn.json whenever building...

Maybe publish a syn-data crate that depends on the matching version of syn and just provides syn.json and/or a pub const SYN_JSON: &'static str?