Clear sockets perform worse than TLS socket in some cases

• Version: v13.0.0-pre
• Platform: Linux tufopad 4.15.0-48-generic #51-Ubuntu SMP Wed Apr 3 08:28:49 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
• Subsystem: net

While writing and performing tests for this issue opened by @alexfernandez and fixed by @jmendeth, I noticed that in some cases, clear connections seem to perform worse than TLS connections, specially after the fix that enhances significantly the performance of the TLS connections. I will patch the existing secure-pair benchmark test to expose the issue.

The performance of clear connections seems to be the same across node versions (I've tested it in node 8, 10 and 13-pre). This means that this issue is not a regression, but an enhancement, and the fix needed is probably very similar to the one that solved the secure-pair performance issue.

Commencez par le test de benchmark secure-pair existant mentionné dans l’issue et comparez ses cas clear et TLS ; examinez l’issue #20263 et la PR #27861 pour voir la modification de performance associée. Le travail est considéré comme terminé lorsque le benchmark met en évidence le ralentissement des sockets clear et que l’implémentation de net est améliorée afin que les connexions clear ne soient plus moins performantes dans les cas signalés.