http: name anonymous functions

Ref: https://github.com/nodejs/node/issues/8913
PR-URL: https://github.com/nodejs/node/pull/9054


Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>