Make underscore number parsing independent of "CYTHON_USE_TYPE_SLOTS" guard.

Cython/Utility/Optimize.c

@@ -601,23 +601,21 @@ static double __Pyx__PyObject_AsDouble(PyObject* obj); /* proto */
 //@requires: ObjectHandling.c::PyObjectCallOneArg
 
 static double __Pyx__PyObject_AsDouble(PyObject* obj) {
+    if (PyUnicode_CheckExact(obj)) {
+        return __Pyx_PyUnicode_AsDouble(obj);
+    } else if (PyBytes_CheckExact(obj)) {
+        return __Pyx_PyBytes_AsDouble(obj);
+    } else if (PyByteArray_CheckExact(obj)) {
+        return __Pyx_PyByteArray_AsDouble(obj);
+    } else {
         PyObject* float_value;
 #if !CYTHON_USE_TYPE_SLOTS
         float_value = PyNumber_Float(obj);  if ((0)) goto bad;
         // avoid "unused" warnings
         (void)__Pyx_PyObject_CallOneArg;
-    (void)__Pyx_PyBytes_AsDouble;
-    (void)__Pyx_PyByteArray_AsDouble;
-    (void)__Pyx_PyUnicode_AsDouble;
 #else
         PyNumberMethods *nb = Py_TYPE(obj)->tp_as_number;
-    if (PyUnicode_CheckExact(obj)) {
-        return __Pyx_PyUnicode_AsDouble(obj);
-    } else if (PyBytes_CheckExact(obj)) {
-        return __Pyx_PyBytes_AsDouble(obj);
-    } else if (PyByteArray_CheckExact(obj)) {
-        return __Pyx_PyByteArray_AsDouble(obj);
-    } else if (likely(nb) && likely(nb->nb_float)) {
+        if (likely(nb) && likely(nb->nb_float)) {
             float_value = nb->nb_float(obj);
             if (likely(float_value) && unlikely(!PyFloat_Check(float_value))) {
                 __Pyx_TypeName float_value_type_name = __Pyx_PyType_GetName(Py_TYPE(float_value));
@@ -637,6 +635,7 @@ static double __Pyx__PyObject_AsDouble(PyObject* obj) {
             Py_DECREF(float_value);
             return value;
         }
+    }
 bad:
     return (double)-1;
 }