patch 8.2.5046: vim_regsub() can overwrite the destination

Problem:    vim_regsub() can overwrite the destination.
Solution:   Pass the destination length, give an error when it doesn't fit.
diff --git a/src/version.c b/src/version.c
index f1b7010..b7693de 100644
--- a/src/version.c
+++ b/src/version.c
@@ -735,6 +735,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    5046,
+/**/
     5045,
 /**/
     5044,