Invalid "function not used" warning for functions with default valued parameter.

[gallandarakhneorg]

Let the SARL code:

class X {
    private def f1(a : int = 0) : void {
    }
    def f2 {
         f1
    }
}

The previous code causes a warning "f1 is never used".
It is not true because f1 is called without argument, i.e. the default valued parameter is not considered when checking the calls to the functions.