stop pinning self and frame

before: r0-message , r1-self , r2-frame , r3-new_message , r4 + tmps
now: r0-message , r1-new_message , r2 + tmps
programs got smaller, less fuss
also fix in return implementation that got the address from the wrong
message

lib/virtual/passes/enter_implementation.rb

@@ -7,10 +7,6 @@ module Virtual
         new_codes = []
         # save return register to the message at instance return_address
         new_codes << Register.save_return(code, :message , :return_address)
-        # and create a new frame if needed
-        unless code.method.locals.empty?
-          new_codes <<  Register.get_slot( code, :message , :frame , Register.resolve_to_register(:frame))
-        end
         block.replace(code , new_codes )
       end
     end