8031359: Invocable.getInterface() works incorrectly if interface has default methods
Reviewed-by: attila, hannesw
int method 2
double method 2
string method 2
int method 3: 10
double method 3: 10.0
double method 3: 10.2
double method 3: NaN
int method 4: 10
double method 4: 10.2
double method 4: NaN