avoid roundtrip

Author: timfel

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

@@ -44,5 +44,5 @@ PyTypeObject PyBaseObject_Type = PY_TRUFFLE_TYPE("object", &PyType_Type, Py_TPFL
 PyTypeObject PySuper_Type = PY_TRUFFLE_TYPE("super", &PyType_Type, Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC | Py_TPFLAGS_BASETYPE);
 
 int PyType_IsSubtype(PyTypeObject* a, PyTypeObject* b) {
-    return as_int(truffle_invoke(PY_TRUFFLE_CEXT, "PyType_IsSubtype", to_java((PyObject*)a), to_java((PyObject*)b)));
+    return polyglot_as_i32(polyglot_invoke(PY_TRUFFLE_CEXT, "PyType_IsSubtype", to_java((PyObject*)a), to_java((PyObject*)b)));
 }

graalpython/lib-graalpython/python_cext.py

@@ -680,7 +680,7 @@ def PyObject_Repr(o):
 
 
 def PyType_IsSubtype(a, b):
-    return b in a.mro()
+    return 1 if b in a.mro() else 0
 
 
 @may_raise