PFunction: missing setting the METHOD_DESCRIPTOR flag

Author: cosminbasca

graalpython/com.oracle.graal.python.cext/src/functionobject.c

@@ -40,7 +40,7 @@
  */
 #include "capi.h"
 
-PyTypeObject PyFunction_Type = PY_TRUFFLE_TYPE("function", &PyType_Type, Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC, sizeof(PyFunctionObject));
+PyTypeObject PyFunction_Type = PY_TRUFFLE_TYPE("function", &PyType_Type, Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC | Py_TPFLAGS_METHOD_DESCRIPTOR, sizeof(PyFunctionObject));
 
 PyObject* PyClassMethod_New(PyObject* method) {
     return UPCALL_O(PY_BUILTIN, polyglot_from_string("classmethod", SRC_CS), native_to_java(method));

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/type/TypeNodes.java

@@ -177,10 +177,10 @@ static long doBuiltinClassType(PythonBuiltinClassType clazz) {
                 case PBytes:
                     result = DEFAULT | BASETYPE | BYTES_SUBCLASS;
                     break;
+                case PFunction:
                 case PBuiltinFunction:
                     result = DEFAULT | HAVE_GC | METHOD_DESCRIPTOR;
                     break;
-                case PFunction:
                 case PMethod:
                 case PBuiltinMethod:
                 case GetSetDescriptor: