Introduce a benchmarking infrastructure

[axic]

The goal would be to efficiently benchmark EE execution.

I have a prototype using criterion and @s1na has one introducing new host functions for start/stop benchmarking.

[s1na]

I measured elapsed time of the EE as a black box, but also wanted to benchmark specific parts of the EE. That's why I added the new host functions. Maybe they could be in something like the debug namespace?