Merge pull request #65298 from nikhita/cherrypick-jsoniter-bump-1.9

Automatic merge from submit-queue.

Manual cherrypick of #65034 to 1.9: make json serializer case sensitive

fixes partially https://github.com/kubernetes/kubernetes/issues/64612

This PR imports the latest jsoniterator library so that case sensitivity during unmarshalling is optional. The PR also sets Kubernetes json serializer to be case sensitive.

**Release note**:

```release-note
ACTION REQUIRED: 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.
```

/sig api-machinery
/kind bug
/assign caesarxuchao liggitt thockin sttts mbohlool

Kubernetes-commit: f4cf484c2cb6056e28fb9759a3c913be3eed990a

vendor/github.com/modern-go/reflect2/unsafe_struct.go

@@ -0,0 +1,59 @@
+package reflect2
+
+import (
+	"reflect"
+	"unsafe"
+)
+
+type UnsafeStructType struct {
+	unsafeType
+	likePtr bool
+}
+
+func newUnsafeStructType(cfg *frozenConfig, type1 reflect.Type) *UnsafeStructType {
+	return &UnsafeStructType{
+		unsafeType: *newUnsafeType(cfg, type1),
+		likePtr:    likePtrType(type1),
+	}
+}
+
+func (type2 *UnsafeStructType) LikePtr() bool {
+	return type2.likePtr
+}
+
+func (type2 *UnsafeStructType) Indirect(obj interface{}) interface{} {
+	objEFace := unpackEFace(obj)
+	assertType("Type.Indirect argument 1", type2.ptrRType, objEFace.rtype)
+	return type2.UnsafeIndirect(objEFace.data)
+}
+
+func (type2 *UnsafeStructType) UnsafeIndirect(ptr unsafe.Pointer) interface{} {
+	if type2.likePtr {
+		return packEFace(type2.rtype, *(*unsafe.Pointer)(ptr))
+	}
+	return packEFace(type2.rtype, ptr)
+}
+
+func (type2 *UnsafeStructType) FieldByName(name string) StructField {
+	structField, found := type2.Type.FieldByName(name)
+	if !found {
+		return nil
+	}
+	return newUnsafeStructField(type2, structField)
+}
+
+func (type2 *UnsafeStructType) Field(i int) StructField {
+	return newUnsafeStructField(type2, type2.Type.Field(i))
+}
+
+func (type2 *UnsafeStructType) FieldByIndex(index []int) StructField {
+	return newUnsafeStructField(type2, type2.Type.FieldByIndex(index))
+}
+
+func (type2 *UnsafeStructType) FieldByNameFunc(match func(string) bool) StructField {
+	structField, found := type2.Type.FieldByNameFunc(match)
+	if !found {
+		panic("field match condition not found in " + type2.Type.String())
+	}
+	return newUnsafeStructField(type2, structField)
+}