def resolve_and_add(slot , compiler)
      index = resolve_index( slot )
      new_left = get_new_left( slot , compiler )
      compiler.add_code Risc::SlotToReg.new( "SlotLoad #{type}[#{slot}]" , self ,index, new_left)
      new_left
    end
def resolve_and_add(slot , compiler)
      index = resolve_index( slot )
      new_left = get_new_left( slot , compiler )
      compiler.add_code Risc::SlotToReg.new( "SlotLoad #{type}[#{slot}]" , self ,index, new_left)
      new_left
    end
using the registers type, resolve the slot to an index
 Using the index and the register, add a SlotToReg to the instruction