url: name anonymous functions in url

Name anonymous functions in url.js.

PR-URL: https://github.com/nodejs/node/pull/9225
Ref: https://github.com/nodejs/node/issues/8913


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Franziska Hinkelmann <franziska.hinkelmann@gmail.com>