change return sequence to return messages to space

as it was before blocks
(thought blocks would make reuse of messages impossible, but was wrong, this only appilies to lambdas)
(too) many tests affected

test/mom/helper.rb

@@ -12,8 +12,9 @@ module Risc
       [ Label ]
     end
     def postamble
-      [Label, SlotToReg, SlotToReg, RegToSlot, SlotToReg,
-        SlotToReg, SlotToReg, FunctionReturn, Label]
+      [Label, SlotToReg, SlotToReg, RegToSlot, LoadConstant ,
+        SlotToReg, RegToSlot, RegToSlot, SlotToReg, SlotToReg,
+        SlotToReg , FunctionReturn, Label]
     end
     # test hack to in place change object type
     def add_space_field(name,type)