Transfer type inference of the expression to the var

Brain dump on this behavior:

• Core issue (def x (constructor....)) x is dynamic
  • or more generally the inference of the expression doesn't transfer to the var
  • thus the user has to type hint the var itsef
• Why is it like that?
  • Because so does Clojure
  • Because if you redef and that the inferred type change you have to recompile every code referring this var (and this may cascade) thus promising nothing is easier.
• Right now we transitively recompile all dependants so we could transfer the inferred type without adding complexity. It will impact REPL design though, maybe stick to a broadly sweeping dependants recompilation for REPL too.
• Conceptually the inferred type may be too precise when you think of types as contracts.

Start by reviewing the issue's discussion of (def x (constructor....)), inferred types, redefinition, and dependent recompilation. Determine the design for transferring an expression's inferred type to its var while accounting for REPL recompilation and type-contract precision; done means the behavior and recompilation implications are resolved.