Don't warn for uses of old property syntax in utility code.

Cython/Compiler/ParseTreeTransforms.py

@@ -1295,6 +1295,8 @@ class DecoratorTransform(ScopeTrackingTransform, SkipDeclarations):
         return node
 
     def visit_PropertyNode(self, node):
+        # Suppress warning for our code until we can convert all our uses over.
+        if isinstance(node.pos[0], str) or True:
             warning(node.pos, "'property %s:' syntax is deprecated, use '@property'" % node.name, 2)
         return node