When the GC calls the matchers deinit function, the milist (also an GC-able
object) might already have been deinitialized, so we can't use the count
values from there.
Maybe milist should actually be refcounted? It doesn't build cycles and
doesn't reference other GC objects. This would simplify it and remove the
now duplicated count data.
This allows the destructuring of lists into individual values.
We can have arbitrarily nested lists, can check for constant values and can
have up to one '~'-prefixed variable per list, that will capture the
remaining elements of the list.
It is implemented as a second set of bytecode instructions, which define a
matcher. These matchers should also enable us to implement the same pattern
matching capabiities for function parameters.
Not all matching features are implemented yet, predicate matching and
matching into a dictionary key is not implemented yet.
