patch 8.2.1680: Vim9: line number for compare error is wrong

Problem:    Vim9: line number for compare error is wrong.
Solution:   Set SOURCING_LNUM. (closes #6936)
diff --git a/src/version.c b/src/version.c
index a04f93c..89ef82a 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1680,
+/**/
     1679,
 /**/
     1678,