test case for ticket 232 (without __new__ support)

tests/bugs/ext_instance_type_T232.pyx

+__doc__ = u"""
+>>> set_attr(5)
+>>> get_attr()
+None
+"""
+
+cdef class MyExt:
+    cdef object attr
+
+def set_attr(value):
+    MyExt().attr = value
+
+def get_attr():
+    return MyExt().attr