patch 8.0.0676: crash when closing quickfix window in autocmd

Problem:    Crash when closing the quickfix window in a FileType autocommand
            that triggers when the quickfix window is opened.
Solution:   Save the new value before triggering the OptionSet autocommand.
            Add the "starting" flag to test_override() to make the text work.

src/version.c

@@ -764,6 +764,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    676,
 /**/
     675,
 /**/