More useful fixed-size array literals

[Namespace via Digitalmars-d]

> I remember Kenji is not fond of this []s syntax, for reasons I 
> don't remember. Do you think there are other better/different 
> solutions?
>
> Bye,
> bearophile

Read it on my closed Pull Request:
https://github.com/D-Programming-Language/dmd/pull/2952

Another attempt was also closed:
https://github.com/D-Programming-Language/dmd/pull/2958