Allow non-constructor term names to start with :

[S11001001]

In Ermine-Scala, a leading : can be used for both data constructors and ordinary term names, like so:

infix 0 :=
(:=) : forall a b c. (a -> b -> c) -> a -> b -> c
(:=) = id

It would be nice to keep doing this in this Ermine.

[ekmett]

I confess that while it is kind of nice, one of the biggest pain points working on the compiler right now is the lack of a clear indicator that something is a constructor, leading to unbound variables with names like Nothing, so I'm somewhat leaning towards letting these die, as they do actively get in the way of things like destructuring assignment.