parse.y: hide anonymous id

* parse.y (rb_id_attrset): should not reveal anonymous ID as an
  instance variable.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45784 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

parse.y

@@ -8846,7 +8846,7 @@ rb_id_attrset(ID id)
 				  scope, (VALUE)data);
 		}
 		else {
-		    rb_name_error(id, "cannot make unknown type ID %d:%"PRIxVALUE" attrset",
+		    rb_name_error_str(Qnil, "cannot make unknown type anonymous ID %d:%"PRIxVALUE" attrset",
 				      scope, (VALUE)id);
 		}
 	    }