Upgrade xorm to v0.8.0 (#8536)

vendor/xorm.io/xorm/json.go

@@ -0,0 +1,31 @@
+// Copyright 2019 The Xorm Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package xorm
+
+import "encoding/json"
+
+// JSONInterface represents an interface to handle json data
+type JSONInterface interface {
+	Marshal(v interface{}) ([]byte, error)
+	Unmarshal(data []byte, v interface{}) error
+}
+
+var (
+	// DefaultJSONHandler default json handler
+	DefaultJSONHandler JSONInterface = StdJSON{}
+)
+
+// StdJSON implements JSONInterface via encoding/json
+type StdJSON struct{}
+
+// Marshal implements JSONInterface
+func (StdJSON) Marshal(v interface{}) ([]byte, error) {
+	return json.Marshal(v)
+}
+
+// Unmarshal implements JSONInterface
+func (StdJSON) Unmarshal(data []byte, v interface{}) error {
+	return json.Unmarshal(data, v)
+}