vim-patch:9.1.0797: testing of options can be further improved (#30893)

Problem:  testing of options can be further improved
Solution: split the generated option test into test_options_all.vim,
          add more test cases, save and restore values, fix use-after-free

closes: vim/vim#15894

6eca04e9f1

Co-authored-by: Milly <milly.ca@gmail.com>

scripts/gen_eval_files.lua

@@ -670,7 +670,7 @@ local function scope_to_doc(s)
     return m[s[1]]
   end
   assert(s[1] == 'global')
-  return 'global or ' .. m[s[2]] .. ' |global-local|'
+  return 'global or ' .. m[s[2]] .. (s[2] ~= 'tab' and ' |global-local|' or '')
 end
 
 -- @param o vim.option_meta