lib: avoid recompilation of anonymous functions

Since at least V8 5.4, using function.bind() is now fast enough to
use to avoid recompiling/reoptimizing the same anonymous functions.
These changes especially impact http servers.

PR-URL: https://github.com/nodejs/node/pull/6533


Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Fedor Indutny <fedor.indutny@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>