Fix _PyOS_GetOpt() error message for non-ASCII characters (#158626)

Replace %c with %lc.

Author: vstinner

Lib/test/test_cmd_line.py

@@ -684,7 +684,7 @@ def test_del___main__(self):
 
     @support.cpython_only
     def test_unknown_options(self):
-        # Test unknown option -a
+        # Test unknown option
         for option in ('-z', '--long-option', '---'):
             with self.subTest(option=option):
                 rc, out, err = assert_python_failure('-E', option)

Python/getopt.c

@@ -160,7 +160,7 @@ _PyOS_GetOpt(struct _PyOS_GetOpt *getopt)
     wchar_t *ptr = wcschr(SHORT_OPTS, option);
     if (ptr == NULL) {
         if (error) {
-            fprintf(stderr, "Unknown option: -%c\n", (char)option);
+            fprintf(stderr, "Unknown option: -%lc\n", option);
         }
         return '_';
     }
@@ -174,7 +174,7 @@ _PyOS_GetOpt(struct _PyOS_GetOpt *getopt)
             if (getopt->index >= argc) {
                 if (error) {
                     fprintf(stderr,
-                        "Argument expected for the -%c option\n", (char)option);
+                        "Argument expected for the -%lc option\n", option);
                 }
                 return '_';
             }