work on jump insertion continues

Now registering CodeListener instead of PositionListener
Also instead of on the previous, in itself, which is simpler
and allows to react to insertion at end

lib/risc/machine.rb

@@ -121,7 +121,8 @@ module Risc
       Parfait.object_space.types.values.each do |type|
         next unless type.methods
         type.methods.each_method do |method|
-          last_code = CodeListener.init(method.binary , code_start)
+          last_code = CodeListener.init(method.binary)
+          last_code.set(code_start)
           first_position = InstructionListener.init(method.cpu_instructions, method.binary)
           first_position.set( code_start + Parfait::BinaryCode.byte_offset)
           last_code.position_listener( prev_code.object) if prev_code