pythongh-83714: Fix a compiler warning in stat_nanosecond_timestamp() (python#141043)

Disable the fast path on systems with 32-bit long.

Author: vstinner

Modules/posixmodule.c

@@ -2634,11 +2634,14 @@ _posix_free(void *module)
 static PyObject *
 stat_nanosecond_timestamp(_posixstate *state, time_t sec, unsigned long nsec)
 {
+#if SIZEOF_LONG >= 8
     /* 1677-09-21 00:12:44 to 2262-04-11 23:47:15 UTC inclusive */
     if ((LLONG_MIN/SEC_TO_NS) <= sec && sec <= (LLONG_MAX/SEC_TO_NS - 1)) {
         return PyLong_FromLongLong(sec * SEC_TO_NS + nsec);
     }
-    else {
+    else
+#endif
+    {
         PyObject *ns_total = NULL;
         PyObject *s_in_ns = NULL;
         PyObject *s = _PyLong_FromTime_t(sec);