remove virtual new_frame instruction

resolved to one register instruction, not worth the hassle

lib/virtual/instruction.rb

@@ -17,4 +17,3 @@ require_relative "instructions/halt"
 require_relative "instructions/method_call"
 require_relative "instructions/method_enter"
 require_relative "instructions/method_return"
-require_relative "instructions/new_frame"

lib/virtual/instructions/new_frame.rb

@@ -1,6 +0,0 @@
-module Virtual
-
-  class NewFrame < Instruction
-  end
-
-end

lib/virtual/passes/enter_implementation.rb

@@ -9,7 +9,7 @@ module Virtual
         new_codes << Register.save_return(code, :message , :return_address)
         # and create a new frame if needed
         unless code.method.locals.empty?
-          new_codes << Virtual::NewFrame.new
+          new_codes <<  Register.get_slot( code, :message , :frame , Register.resolve_to_register(:frame))
         end
         block.replace(code , new_codes )
       end