Add support for tuplerecords

[saecki]

So there already are arrayrecords like:

record A
    {string}
    a: integer
end

It would be great if there could be tuplerecords like:

record A
    {string, string, integer}
    a: integer
end

[hishamhm]

That does sound like a good idea!...

[lenscas]

What about allowing this:

record A
    [1] string
 end

(or, maybe even without the [] part?)

[hishamhm]

If anyone is willing to try their hand at a PR, I'd rather have the syntax originally suggested by @Saecki , I think it'd be more consistent with the existing array records:

record A
    {string, string, integer}
    a: integer
end