Fix type of heaptype fields

Author: msimacek

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/cext/structs/CFields.java

@@ -285,10 +285,10 @@ public enum CFields {
     PyHeapTypeObject__as_mapping(PyMappingMethods),
     PyHeapTypeObject__as_sequence(PySequenceMethods),
     PyHeapTypeObject__as_buffer(PyBufferProcs),
-    PyHeapTypeObject__ht_name(PyObjectPtr),
-    PyHeapTypeObject__ht_slots(PyObjectPtr),
-    PyHeapTypeObject__ht_qualname(PyObjectPtr),
-    PyHeapTypeObject__ht_module(PyObjectPtr),
+    PyHeapTypeObject__ht_name(PyObject),
+    PyHeapTypeObject__ht_slots(PyObject),
+    PyHeapTypeObject__ht_qualname(PyObject),
+    PyHeapTypeObject__ht_module(PyObject),
 
     PyBytesObject__ob_shash(Py_hash_t),
     PyBytesObject__ob_sval(CHAR_PTR),