Fix type inference.

Cython/Compiler/ExprNodes.py

@@ -5363,7 +5363,7 @@ class CallNode(ExprNode):
                     elif function.entry.name in Builtin.types_that_construct_their_instance:
                         return result_type
         func_type = self.function.analyse_as_type(env)
-        if func_type.is_struct_or_union or func_type.is_cpp_class:
+        if func_type and (func_type.is_struct_or_union or func_type.is_cpp_class):
             return func_type
         return py_object_type