support returned function in relay.build (#10502)

* fix InferType bug

* fix InferType related bug

* support returned function in relay.build

* support returned function in relay.build

* support returned function in relay.build

* support returned function in relay.build

* add warning about function returning function

Author: haoyang9804

src/relay/backend/utils.cc

@@ -1,3 +1,4 @@
+
 /*
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
@@ -139,6 +140,7 @@ int64_t CalculateRelayExprSizeBytes(const Type& expr_type) {
     return size;
   }
   auto tensor_type = expr_type.as<TensorTypeNode>();
+  ICHECK(tensor_type);
   auto shape = tensor_type->shape;
   int num_of_elements = 1;
   for (const auto& dim_index_expr : shape) {