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>
diff --git a/src/version.c b/src/version.c
index 5d1c1c9..e408dc1 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2001,
+/**/
     2000,
 /**/
     1999,