first steps to defining specialised slot classes

getting rid of the mess in SlotDefinition (wip)

test/sol/send/test_send_self.rb

@@ -8,7 +8,7 @@ module Sol
       "self.get_internal_word(0);return"
     end
     def test_receiver
-      assert_equal SlotDefinition,  @ins.next.receiver.class
+      assert_equal MessageDefinition,  @ins.next.receiver.class
     end
     def test_arg_one
       assert_equal SlotLoad,  @ins.next(1).arguments[0].class
@@ -22,6 +22,10 @@ module Sol
     def test_call_has_right_method
       assert_equal :get_internal_word,  @ins.next(2).method.name
     end
+    def test_receiver_move
+      assert_equal MessageDefinition,  @ins.next.receiver.class
+    end
+
   end
   class TestSendSelfImplicitSlotMachine < TestSendSelfSlotMachine