Add tasks for all the new languages

Task/Constrained-genericity/Sidef/constrained-genericity.sidef

@@ -0,0 +1,7 @@
+class FoodBox(*food { .all { .respond_to(:eat) } }) { }
+
+class Fruit { method eat { ... } }
+class Apple < Fruit {  }
+
+say FoodBox(Fruit(), Apple()).dump  #=> FoodBox(food: [Fruit(), Apple()])
+say FoodBox(Apple(), "foo")         #!> ERROR: class `FoodBox` !~ (Apple, String)