Linking examples within rustdoc

[bjorn3]

@jyn514

I think serializing a DefId would be more robust, but IIRC we tried this last week and it didn't work. I would either ask on Zulip the recommended way to do this or we might even need to ask for a way to serialize custom metadata depending on the command

Can you serialize tcx.crate_hash(def_id.krate) combined with the tcx.def_path(*def_id).to_string_no_crate_verbose() you are already serializing? CrateNum is a number referencing a crate with a specific SVH (tcx.crate_hash). This mapping is different for each compilation session.