Humble benchmark (fisher's exact test)

[Ki Rill]

On Saturday, 14 August 2021 at 10:26:52 UTC, John Colvin wrote:
> On Saturday, 14 August 2021 at 02:19:02 UTC, Ki Rill wrote:
>> It's a simple benchmark examining:
>> * execution time (sec)
>> * memory consumption (kb)
>> * binary size (kb)
>> * conciseness of a programming language (lines of code)
>>
>> [Link](https://github.com/rillki/humble-benchmarks/tree/main/fishers-exact-test)
>
> Lots of things to improve there.
>
> https://github.com/rillki/humble-benchmarks/pull/4
>
> A nice quick morning exercise :)

I have added the proposed changes. The performance of D increased 
to almost that of C with ~1-2 seconds difference if using LDC!

The betterC version is still slightly faster though.

To sum up:
```
Clang C           9.1 s
Clang C++         9.4 s
LDC Das betterC   10.3 s
LDC D libC math   12.2 s
Rust              13 s
```

Thank you John for you invaluable help! I didn't know that Phobos 
math is twice as slow as libC math.