Revert "Always bind Cython functions"

This reverts commit 66773260.

Cython/Utility/CythonFunction.c

@@ -548,6 +548,21 @@ static int __Pyx_CyFunction_traverse(__pyx_CyFunctionObject *m, visitproc visit,
 
 static PyObject *__Pyx_CyFunction_descr_get(PyObject *func, PyObject *obj, PyObject *type)
 {
+    __pyx_CyFunctionObject *m = (__pyx_CyFunctionObject *) func;
+
+    if (m->flags & __Pyx_CYFUNCTION_STATICMETHOD) {
+        Py_INCREF(func);
+        return func;
+    }
+
+    if (m->flags & __Pyx_CYFUNCTION_CLASSMETHOD) {
+        if (type == NULL)
+            type = (PyObject *)(Py_TYPE(obj));
+        return __Pyx_PyMethod_New(func, type, (PyObject *)(Py_TYPE(type)));
+    }
+
+    if (obj == Py_None)
+        obj = NULL;
     return __Pyx_PyMethod_New(func, obj, type);
 }
 

tests/run/cyfunction.pyx

@@ -376,18 +376,6 @@ class TestUnboundMethod:
     def meth(self): pass
 
 
-class TestStaticmethod(object):
-    """
-    >>> x = TestStaticmethod()
-    >>> x.staticmeth(42)
-    42
-    >>> x.staticmeth.__get__(42)()
-    42
-    """
-    @staticmethod
-    def staticmeth(arg): return arg
-
-
 cdef class TestOptimisedBuiltinMethod:
     """
     >>> obj = TestOptimisedBuiltinMethod()