Scala3: Don't emit static calls to object methods, use method dispatch instead

[WojciechMazur]

Based on com-lihaoyi/unroll#9

We should fix compiler plugin to always generate pair or instructions method + call instead of a direct call to statically known function. Optimizer would replace method dispatch of method with a single implementation with a virtual call. It would allow the API to evolve in binary compatible way - in case of mention issue it was moving method from object to implemented trait.