Allow staticmethod in non-decorator contexts.

Cython/Compiler/ParseTreeTransforms.py

@@ -2555,7 +2555,7 @@ class TransformBuiltinMethods(EnvTransform):
                 node = ExprNodes.StringNode(node.pos, value=EncodedString(version))
             elif attribute == u'NULL':
                 node = ExprNodes.NullNode(node.pos)
-            elif attribute in (u'set', u'frozenset'):
+            elif attribute in (u'set', u'frozenset', u'staticmethod'):
                 node = ExprNodes.NameNode(node.pos, name=EncodedString(attribute),
                                           entry=self.current_env().builtin_scope().lookup_here(attribute))
             elif PyrexTypes.parse_basic_type(attribute):

tests/run/staticmethod.pyx

@@ -120,3 +120,12 @@ cdef class ArgsKwargs(object):
         (1, 2, ('a', 3))
         """
         return args + tuple(sorted(kwargs.items()))
+
+class StaticmethodSubclass(staticmethod):
+    """
+    >>> s = StaticmethodSubclass(None)
+    >>> s.is_subtype()
+    True
+    """
+    def is_subtype(self):
+        return isinstance(self, staticmethod)