patch 8.2.3521: options completion test fails

Problem:    Options completion test fails.
Solution:   Add 'thesaurusfunc' to the results.

src/testdir/test_options.vim

@@ -256,7 +256,7 @@ func Test_set_completion()
 
   " Expand abbreviation of options.
   call feedkeys(":set ts\<C-A>\<C-B>\"\<CR>", 'tx')
-  call assert_equal('"set tabstop thesaurus ttyscroll', @:)
+  call assert_equal('"set tabstop thesaurus thesaurusfunc ttyscroll', @:)
 
   " Expand current value
   call feedkeys(":set fileencodings=\<C-A>\<C-B>\"\<CR>", 'tx')

src/version.c

@@ -757,6 +757,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    3521,
 /**/
     3520,
 /**/