swift234

Produce an error for generic parameters of functions if those parameters are not used in function signature.

If a generic parameter is not referred to from a function signature, it can never be inferred and thus such a function can never be invoked.

We now produce the following error:

There is no way to infer the generic parameter 'T' if it is not used in function signature
func f8<T> (x: Int) {}
             ^

Swift SVN r28181