patch 8.0.0488: running tests leaves an "xxx" file behind

Problem:    Running tests leaves an "xxx" file behind.
Solution:   Delete the 'verbosefile' after resetting the option.
diff --git a/src/testdir/gen_opt_test.vim b/src/testdir/gen_opt_test.vim
index 16723be..b69ae67 100644
--- a/src/testdir/gen_opt_test.vim
+++ b/src/testdir/gen_opt_test.vim
@@ -175,10 +175,6 @@
       for val in a[0]
 	call add(script, 'set ' . name . '=' . val)
 	call add(script, 'set ' . shortname . '=' . val)
-
-	if name == 'verbosefile' && !empty(val)
-	  call add(script, 'call delete("'. val. '")')
-	endif
       endfor
 
       " setting an option can only fail when it's implemented.
@@ -192,6 +188,9 @@
 
     call add(script, 'set ' . name . '&')
     call add(script, 'set ' . shortname . '&')
+    if name == 'verbosefile'
+      call add(script, 'call delete("xxx")')
+    endif
 
     if name == 'more'
       call add(script, 'set nomore')
diff --git a/src/version.c b/src/version.c
index c9d7361..c620780 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    488,
+/**/
     487,
 /**/
     486,