add test constellation for unknown operator

Author: Reinhold Bertram

test_check.m

@@ -126,3 +126,7 @@
 tokens = tokenize_code('....');
 assert(tokens(1).hasType('punctuation'));
 assert(tokens(2).hasType('comment'));
+
+tokens = tokenize_code('.*...');
+assert(tokens(1).hasType('punctuation'));
+assert(tokens(2).hasType('punctuation'));