use SIZEOF_SIZE_T == 8

Author: chris-eibl

Objects/longobject.c

@@ -909,7 +909,7 @@ _PyLong_NumBits(PyObject *vv)
     assert(ndigits == 0 || v->long_value.ob_digit[ndigits - 1] != 0);
     if (ndigits > 0) {
         digit msd = v->long_value.ob_digit[ndigits - 1];
-#if SIZEOF_SIZE_T > 4
+#if SIZEOF_SIZE_T == 8
         assert(ndigits <= INT64_MAX / PyLong_SHIFT);
 #endif
         result = (int64_t)(ndigits - 1) * PyLong_SHIFT;