bpo-36048: Use __index__() instead of __int__() for implicit conversion if available. (GH-11952)

Deprecate using the __int__() method in implicit conversions of Python
numbers to C integers.

Modules/arraymodule.c

@@ -340,7 +340,7 @@ get_int_unless_float(PyObject *v)
                         "array item must be integer");
         return NULL;
     }
-    return (PyObject *)_PyLong_FromNbInt(v);
+    return _PyLong_FromNbIndexOrNbInt(v);
 }
 
 static int