support 'object' as type in cython.declare()

Cython/Shadow.py

@@ -144,7 +144,7 @@ def address(arg):
     return pointer(type(arg))([arg])
 
 def declare(type=None, value=_Unspecified, **kwds):
-    if type is not None and hasattr(type, '__call__'):
+    if type not in (None, object) and hasattr(type, '__call__'):
         if value is not _Unspecified:
             return type(value)
         else: