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/risc/interpreter/test_events.rb

@@ -19,7 +19,7 @@ module Risc
       @instruction_events << was
     end
     def length
-      40
+      45
     end
     def test_state_change
       @interpreter.register_event :state_changed , self
@@ -45,7 +45,8 @@ module Risc
              SlotToReg, RegToSlot, RegToSlot, SlotToReg, RegToSlot,
              SlotToReg, RegToSlot, LoadConstant, RegToSlot, FunctionCall,
              LoadConstant, RegToSlot, Branch, SlotToReg, SlotToReg,
-             RegToSlot, SlotToReg, SlotToReg, SlotToReg, FunctionReturn,
+             RegToSlot, LoadConstant, SlotToReg, RegToSlot, RegToSlot,
+             SlotToReg, SlotToReg, SlotToReg, Branch, FunctionReturn,
              Transfer, SlotToReg, SlotToReg, Branch, Syscall,
              NilClass]
       assert_equal Fixnum , get_return.class