patch 9.0.2001: Vim9: segfault with islocked()

Problem:  Vim9: segfault with islocked()
Solution: Check that the lval pointer is not null for objects and
          class variables

closes: #13295

Signed-off-by: Christian Brabandt <cb@256bit.org>
Co-authored-by: Ernie Rael <errael@raelity.com>

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2001,
 /**/
     2000,
 /**/