fix get_internal_byte

improved operators and tests
some logic errors still

lib/slot_machine/macro/get_internal_byte.rb

@@ -4,9 +4,8 @@ module SlotMachine
       builder = compiler.builder(compiler.source)
       integer_tmp = builder.allocate_int
       builder.build do
-        object! << message[:receiver]
-        integer! << message[:arg1] #"at"
-        integer.reduce_int
+        object = message[:receiver].to_reg
+        integer = message[:arg1].to_reg.reduce_int(false)
         object <= object[integer]
         integer_tmp[Parfait::Integer.integer_index] << object
         message[:return_value] << integer_tmp