Revert vendor directory to support old golang (GOPATH mode)

gomodule is still in progress to migrate for now, hence multus
team decide to keep vendor directory to support build without
gomodule.

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

@@ -0,0 +1,101 @@
+package reflect2
+
+import (
+	"reflect"
+	"unsafe"
+)
+
+type safeMapType struct {
+	safeType
+}
+
+func (type2 *safeMapType) Key() Type {
+	return type2.safeType.cfg.Type2(type2.Type.Key())
+}
+
+func (type2 *safeMapType) MakeMap(cap int) interface{} {
+	ptr := reflect.New(type2.Type)
+	ptr.Elem().Set(reflect.MakeMap(type2.Type))
+	return ptr.Interface()
+}
+
+func (type2 *safeMapType) UnsafeMakeMap(cap int) unsafe.Pointer {
+	panic("does not support unsafe operation")
+}
+
+func (type2 *safeMapType) SetIndex(obj interface{}, key interface{}, elem interface{}) {
+	keyVal := reflect.ValueOf(key)
+	elemVal := reflect.ValueOf(elem)
+	val := reflect.ValueOf(obj)
+	val.Elem().SetMapIndex(keyVal.Elem(), elemVal.Elem())
+}
+
+func (type2 *safeMapType) UnsafeSetIndex(obj unsafe.Pointer, key unsafe.Pointer, elem unsafe.Pointer) {
+	panic("does not support unsafe operation")
+}
+
+func (type2 *safeMapType) TryGetIndex(obj interface{}, key interface{}) (interface{}, bool) {
+	keyVal := reflect.ValueOf(key)
+	if key == nil {
+		keyVal = reflect.New(type2.Type.Key()).Elem()
+	}
+	val := reflect.ValueOf(obj).MapIndex(keyVal)
+	if !val.IsValid() {
+		return nil, false
+	}
+	return val.Interface(), true
+}
+
+func (type2 *safeMapType) GetIndex(obj interface{}, key interface{}) interface{} {
+	val := reflect.ValueOf(obj).Elem()
+	keyVal := reflect.ValueOf(key).Elem()
+	elemVal := val.MapIndex(keyVal)
+	if !elemVal.IsValid() {
+		ptr := reflect.New(reflect.PtrTo(val.Type().Elem()))
+		return ptr.Elem().Interface()
+	}
+	ptr := reflect.New(elemVal.Type())
+	ptr.Elem().Set(elemVal)
+	return ptr.Interface()
+}
+
+func (type2 *safeMapType) UnsafeGetIndex(obj unsafe.Pointer, key unsafe.Pointer) unsafe.Pointer {
+	panic("does not support unsafe operation")
+}
+
+func (type2 *safeMapType) Iterate(obj interface{}) MapIterator {
+	m := reflect.ValueOf(obj).Elem()
+	return &safeMapIterator{
+		m:    m,
+		keys: m.MapKeys(),
+	}
+}
+
+func (type2 *safeMapType) UnsafeIterate(obj unsafe.Pointer) MapIterator {
+	panic("does not support unsafe operation")
+}
+
+type safeMapIterator struct {
+	i    int
+	m    reflect.Value
+	keys []reflect.Value
+}
+
+func (iter *safeMapIterator) HasNext() bool {
+	return iter.i != len(iter.keys)
+}
+
+func (iter *safeMapIterator) Next() (interface{}, interface{}) {
+	key := iter.keys[iter.i]
+	elem := iter.m.MapIndex(key)
+	iter.i += 1
+	keyPtr := reflect.New(key.Type())
+	keyPtr.Elem().Set(key)
+	elemPtr := reflect.New(elem.Type())
+	elemPtr.Elem().Set(elem)
+	return keyPtr.Interface(), elemPtr.Interface()
+}
+
+func (iter *safeMapIterator) UnsafeNext() (unsafe.Pointer, unsafe.Pointer) {
+	panic("does not support unsafe operation")
+}