patch 8.2.3113: no error when for loop variable shadows script variable

Problem:    No error when for loop variable shadows script variable.
Solution:   Check for the error. (closes #8512)
diff --git a/src/testdir/test_vim9_script.vim b/src/testdir/test_vim9_script.vim
index 9d54899..f5dc26e 100644
--- a/src/testdir/test_vim9_script.vim
+++ b/src/testdir/test_vim9_script.vim
@@ -2533,12 +2533,12 @@
 enddef
 
 def Test_for_loop_fails()
-  CheckDefFailure(['for '], 'E1097:')
-  CheckDefFailure(['for x'], 'E1097:')
-  CheckDefFailure(['for x in'], 'E1097:')
-  CheckDefFailure(['for # in range(5)'], 'E690:')
-  CheckDefFailure(['for i In range(5)'], 'E690:')
-  CheckDefFailure(['var x = 5', 'for x in range(5)'], 'E1017:')
+  CheckDefAndScriptFailure2(['for '], 'E1097:', 'E690:')
+  CheckDefAndScriptFailure2(['for x'], 'E1097:', 'E690:')
+  CheckDefAndScriptFailure2(['for x in'], 'E1097:', 'E15:')
+  CheckDefAndScriptFailure(['for # in range(5)'], 'E690:')
+  CheckDefAndScriptFailure(['for i In range(5)'], 'E690:')
+  CheckDefAndScriptFailure2(['var x = 5', 'for x in range(5)', 'endfor'], 'E1017:', 'E1041:')
   CheckScriptFailure(['def Func(arg: any)', 'for arg in range(5)', 'enddef', 'defcompile'], 'E1006:')
   delfunc! g:Func
   CheckDefFailure(['for i in xxx'], 'E1001:')