move each slot instruction into own file

lib/mom/instruction/slot_load.rb

@@ -31,37 +31,12 @@ module Mom
       left = SlotDefinition.new(left.shift , left) if left.is_a? Array
       @left , @right = left , right
       raise "left not SlotDefinition, #{left}" unless left.is_a? SlotDefinition
-#      raise "right not Mom, #{right.to_rxf}" unless right.class.name.include?("Mom")
-    end
-
-    def to_risc(compiler)
-      Risc::Label.new(self,"nosense")
-    end
-
-  end
-
-  # A SlotConstant moves a constant into a known Slot.
-  # Eg when you write a = 5 , the 5 becomes a constant, and so the right side
-  # the a is an instance variable on the current frame, and the frame is an instance
-  # of the current message, so the effect is something like message.frame.a = 5
-  # @left:  See SlotLoad, an array of symbols
-  # @right: A Constant from parse, ie an instance of classes in basc_value, like TrueStatement
-  class SlotConstant < SlotLoad
-
-    def initialize(left , right)
-      super
-      raise "right not constant, #{right}" unless right.is_a? Mom::Constant
-    end
-
-  end
-
-  #SlotMove is a SlotLoad where the right side is a slot, just like the left.
-  class SlotMove < SlotLoad
-    def to_risc(compiler)
-
+      raise "right not Mom, #{right.to_rxf}" unless right.class.name.include?("Mom")
     end
   end
 
+
+
   class SlotDefinition
     attr_reader :known_object , :slots
     def initialize( object , slots)