Parallel Rogue-like benchmark

[bearophile]

Dmitry Olshansky:

>> Regarding what is idiomatic D, isn't `immutable x = rnd.next %
>> levelSize;` pedantic.
>> Why not just go with `const x = rnd.next % levelSize;`
>
> IMHO yes, it's pedantic.

It's a little pedantic, and it's some characters longer than 
"const", but I think it's the good standard to use unless 
something (D implementation bugs, bugs or missing parts in 
Phobos, code logic, etc) prevents you to use it :-)

Bye,
bearophile