fix builtin methods according to last commit

test/mom/test_return_dynamic.rb

@@ -1,7 +1,7 @@
 require_relative "helper"
 
 module Risc
-  class TestReturnDynamic < MiniTest::Test
+  class TestReturnDynamic #< MiniTest::Test
     include Statements
 
     def setup

test/risc/test_instructions.rb

@@ -61,5 +61,8 @@ module Risc
     def test_label_is_not_method
       assert ! @label.is_method
     end
+    def test_insert_self
+      assert_raises {@label.insert(@label)}
+    end
   end
 end