Merge pull request #65157 from caesarxuchao/cherrypick-65034-1.10

Automatic merge from submit-queue.

Manually cherrypick #65034 to 1.10

Manually cherrypicking #65034. Using hack/cherry_pick_pull.sh to cherrypick is difficult because that requires cherrypicking #63059 first.

This PR imported the latest jsoniterator library so that case sensitivity during unmarhsaling is optional. The PR also set Kubernetes json serializer to be case sensitive.

Fix #64612.

```release-notes
Kubernetes json deserializer is now case-sensitive to restore compatibility with pre-1.8 servers.
If your config files contains fields with wrong case, the config files will be now invalid.
```

Kubernetes-commit: 32ac1c9073b132b8ba18aa830f46b77dcceb0723

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

@@ -0,0 +1,42 @@
+package jsoniter
+
+import (
+	"io"
+)
+
+// IteratorPool a thread safe pool of iterators with same configuration
+type IteratorPool interface {
+	BorrowIterator(data []byte) *Iterator
+	ReturnIterator(iter *Iterator)
+}
+
+// StreamPool a thread safe pool of streams with same configuration
+type StreamPool interface {
+	BorrowStream(writer io.Writer) *Stream
+	ReturnStream(stream *Stream)
+}
+
+func (cfg *frozenConfig) BorrowStream(writer io.Writer) *Stream {
+	stream := cfg.streamPool.Get().(*Stream)
+	stream.Reset(writer)
+	return stream
+}
+
+func (cfg *frozenConfig) ReturnStream(stream *Stream) {
+	stream.out = nil
+	stream.Error = nil
+	stream.Attachment = nil
+	cfg.streamPool.Put(stream)
+}
+
+func (cfg *frozenConfig) BorrowIterator(data []byte) *Iterator {
+	iter := cfg.iteratorPool.Get().(*Iterator)
+	iter.ResetBytes(data)
+	return iter
+}
+
+func (cfg *frozenConfig) ReturnIterator(iter *Iterator) {
+	iter.Error = nil
+	iter.Attachment = nil
+	cfg.iteratorPool.Put(iter)
+}