allow reverse syntax for >> (ie <<)

slot >> reg makes sense, being a slot_to_reg
but . . .
consistently use of << (as meaning assignment , =) also makes sense
allow both and let time tell which makes more sense

lib/mom/instruction/message_setup.rb

@@ -54,8 +54,7 @@ module Mom
     def get_message_to( builder )
       builder.build do
         space << Parfait.object_space
-        space[:first_message] >> next_message
+        next_message << space[:first_message]
-        #risc << Risc.slot_to_reg(source + "get next message" , space , :first_message , message)
       end
     end
     def nnop

lib/risc/risc_value.rb

@@ -68,6 +68,8 @@ module Risc
         ins = Risc.load_constant("#{load.class} to #{self.type}" , load , self)
       when RiscValue
         ins = Risc.transfer("#{load.type} to #{self.type}" , load , self)
+      when RValue
+        load >> self
       else
         raise "not implemented"
       end

test/risc/test_builder.rb

@@ -35,6 +35,12 @@ module Risc
       assert_equal SlotToReg , built.class
       assert_equal :r1 , built.array.symbol
     end
+    def test_returns_slot_reverse
+      r2 = RiscValue.new(:r2 , :Message)
+      built = @builder.build{ r2 << space[:first_message] }
+      assert_equal SlotToReg , built.class
+      assert_equal :r1 , built.array.symbol
+    end
     def test_reuses_names
       r1 = RiscValue.new(:r1 , :Space)
       built = @builder.build{ space << r1 ; space << r1}