more renaming ripples

lib/virtual/method_definition.rb

@@ -65,7 +65,7 @@ module Virtual
     def locals_at l_block
       used =[]
       # call assigns the return register, but as it is in l_block, it is not asked.
-      assigned = [ RegisterReference.new(Vm::RegisterMachine.instance.return_register) ]
+      assigned = [ RegisterReference.new(Register::RegisterMachine.instance.return_register) ]
       l_block.reachable.each do |b|
         b.uses.each {|u|
           (used << u) unless assigned.include?(u) 

lib/virtual/plock.rb

@@ -30,7 +30,7 @@ module Virtual
     # Data gets assembled after methods
     def add_data o
       return if @objects.include? o
-      raise "must be derived from Code #{o.inspect}" unless o.is_a? Vm::Code
+      raise "must be derived from Code #{o.inspect}" unless o.is_a? Register::Code
       @data << o # TODO check type , no basic values allowed (must be wrapped)
     end