fix allocate in builder

which accessed unknown types.
also moved assert_allocate to support

lib/slot_machine/slotted_message.rb

@@ -14,8 +14,8 @@ module SlotMachine
     # the code is added to compiler
     # the register returned
     def to_register(compiler, source)
-      slots = @slots
       left = Risc.message_named_reg
+      slots = @slots
       while( slots )
         left = left.resolve_and_add( slots.name , compiler)
         slots = slots.next_slot
@@ -30,7 +30,6 @@ module SlotMachine
     #       They are very similar (apart from the final reg_to_slot here) and should
     #       most likely be united
     def reduce_and_load(const_reg , compiler , original_source )
-      raise "Not Message #{object}" unless known_object == :message
       left = Risc.message_named_reg
       slot = slots
       while( slot.next_slot )