start implementing return for constant

lib/vool/statements/return_statement.rb

@@ -10,5 +10,14 @@ module Vool
       @return_value.collect(arr)
       super
     end
+
+    # To return form a method in mom instructions we need to do three things:
+    # - store the given return value, this is a SlotMove / SlotConstant
+    # - restore the previous message
+    # - jump to the return address
+    def to_mom( method )
+      [Mom::SlotConstant.new([:message , :return_value] , @return_value)]
+    end
+
   end
 end