patch 8.2.0389: delayed redraw when shifting text from Insert mode

Problem:    Delayed redraw when shifting text from Insert mode.
Solution:   Use msg_attr_keep() instead of msg(). (closes #5782)

src/ops.c

@@ -203,7 +203,7 @@ op_shift(oparg_T *oap, int curs_top, int amount)
 	vim_snprintf((char *)IObuff, IOSIZE,
 		NGETTEXT(msg_line_single, msg_line_plural, oap->line_count),
 		oap->line_count, op, amount);
-	msg((char *)IObuff);
+	msg_attr_keep((char *)IObuff, 0, TRUE);
     }
 
     if (!cmdmod.lockmarks)

src/version.c

@@ -738,6 +738,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    389,
 /**/
     388,
 /**/