Merge pull request #48287 from thockin/json-iterator

Automatic merge from submit-queue

Use json-iterator instead of ugorji for JSON.

@smarterclayton @wojtek-t

Fixes #36120
xref #18762

```release-note
Switch JSON marshal/unmarshal to json-iterator library.  Performance should be close to previous with no generated code.
```

Kubernetes-commit: 6a845c67f097cd76f9d90ab3c9c5b5603c70afe4

vendor/github.com/json-iterator/go/feature_any_nil.go

@@ -0,0 +1,69 @@
+package jsoniter
+
+type nilAny struct {
+	baseAny
+}
+
+func (any *nilAny) LastError() error {
+	return nil
+}
+
+func (any *nilAny) ValueType() ValueType {
+	return NilValue
+}
+
+func (any *nilAny) MustBeValid() Any {
+	return any
+}
+
+func (any *nilAny) ToBool() bool {
+	return false
+}
+
+func (any *nilAny) ToInt() int {
+	return 0
+}
+
+func (any *nilAny) ToInt32() int32 {
+	return 0
+}
+
+func (any *nilAny) ToInt64() int64 {
+	return 0
+}
+
+func (any *nilAny) ToUint() uint {
+	return 0
+}
+
+func (any *nilAny) ToUint32() uint32 {
+	return 0
+}
+
+func (any *nilAny) ToUint64() uint64 {
+	return 0
+}
+
+func (any *nilAny) ToFloat32() float32 {
+	return 0
+}
+
+func (any *nilAny) ToFloat64() float64 {
+	return 0
+}
+
+func (any *nilAny) ToString() string {
+	return ""
+}
+
+func (any *nilAny) WriteTo(stream *Stream) {
+	stream.WriteNil()
+}
+
+func (any *nilAny) Parse() *Iterator {
+	return nil
+}
+
+func (any *nilAny) GetInterface() interface{} {
+	return nil
+}