test Text.check: add a space at the start in character reference cases

Author: kou

test/test_text_check.rb

@@ -72,6 +72,11 @@ def test_character_reference_decimal_garbage_at_the_end
         assert_check_failed("&#48x;", "&")
       end
 
+      def test_character_reference_decimal_space_at_the_start
+        # U+0030 DIGIT ZERO
+        assert_check_failed("&# 48;", "&")
+      end
+
       def test_character_reference_decimal_control_character
         # U+0008 BACKSPACE
         assert_check_failed("", "")
@@ -92,6 +97,11 @@ def test_character_reference_hex_garbage_at_the_end
         assert_check_failed("&#x48x;", "&")
       end
 
+      def test_character_reference_hex_space_at_the_start
+        # U+0030 DIGIT ZERO
+        assert_check_failed("&#x 30;", "&")
+      end
+
       def test_character_reference_hex_surrogate_block
         # U+0D800 SURROGATE PAIR
         assert_check_failed("�", "�")