Json Encoding fails on recursion when replaceNodes is disabled

Hi @nikic,

I'm unable to dump a class AST in JSON when using the NameResolver and passing replaceNodes false, because of recursive refs. You can see an example at https://github.com/dhaeckel/php-parser-issue-repro, you have to execute vendor/bin/php-parse -N -j yaf.php and change the NameResolver options in vendor/nikic/php-parser/bin/php-parse to see the problem. A possible mitigation could be to clone already resolved names before returning to break the cyclic refs. See https://github.com/nikic/PHP-Parser/pull/1075 for a possible solution. Let me know, if you need anything from me.

Thanks