Preemptively add "number" as a kind of flexible variable that can unify with an (Is Number)
Preemptively add "number" as a kind of flexible variable that can unify with an (Is Number)

This is similar to the recent issue with comparable brought up by Max.

5outh/Elm,laszlopandy/elm-compiler,deadfoxygrandpa/Elm,pairyo/elm-compiler,mgold/Elm,Axure/elm-compiler,JoeyEremondi/elm-pattern-effects