new syntax: `type` defines multiple types

[zilinc]

type A, B, C

[zilinc]

and also for abstract functions/constants:

const_1, const_2, const_3 : U16

[zilinc]

type A, B, C = U16 looks ambiguous, so we might not implement this feature, unless there're some good suggestions.

[liamoc]

Is this something to put in our syntactic sugar bucket?

[zilinc]

should be, indeed.

[ajaysusarla]

we should be able to do something like type A = U16, B = U32, C = U64 even, I think.

[liamoc]

what about something like type A, B = U16 ? Is that equivalent to:

type A
type B = U16

or

type A = U16
type B = U16

or not permitted?

[zilinc]

originally I thought the latter.. just like typedef.. but as I realised the potential ambiguity I gave up...