patch 8.0.0582: illegal memory access with z= command

Problem:    Illegal memory access with z= command. (Dominique Pelle)
Solution:   Avoid case folded text to be longer than the original text.  Use
            MB_PTR2LEN() instead of MB_BYTE2LEN().
diff --git a/src/version.c b/src/version.c
index 3f74d6e..0533f57 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    582,
+/**/
     581,
 /**/
     580,