False positive on constants

[dwijnand]

As it says in the Scala spec:

in the generated code [references to the constant value x] are replaced by the definition's right-hand side e.

(in SLS 4.1 Value Declarations and Definitions)

Therefore even if it's true that a change in the type of a constant is a change in its binary API there are no call sites in bytecode to worry about. The only breakage is in source compatibility.