Add a Macro Benchmark that Exercises Threading (Multi-Core Concurrency)

From @methane (https://mail.python.org/archives/list/python-dev@python.org/message/KVH7QLJ4VJBQQ45LZTWDXO2SEC6ANX7T/):

CPU cache invalidation exists regardless. With the current GIL the
effect it is reduced significantly.

It's an interesting point. We can not see the benefit from pypeformance, because it doesn't use much data and it runs one process
at a time. So the pyperformance can not make enough stress to the last level cache which is shared by many cores.

We need multiprocess performance benchmark apart from pyperformance, to stress the last level cache from multiple cores. It helps not only this PEP, but also optimizing containers like dict and set.

Comece revisando a suíte de benchmarks existente do pyperformance e como seus benchmarks de processo único são organizados. Defina como um benchmark de multiprocessing deve exercer pressão sobre o cache de último nível compartilhado entre os núcleos e considere o benchmark concluído quando ele fornecer dados de desempenho multicore reproduzíveis e úteis para avaliar otimizações de dict e set.