suport encode map[interface{}]interface{}

config.go

@@ -2,12 +2,12 @@ package jsoniter
 
 import (
 	"encoding/json"
+	"github.com/modern-go/concurrent"
 	"github.com/modern-go/reflect2"
 	"io"
+	"reflect"
 	"sync"
 	"unsafe"
-	"github.com/modern-go/concurrent"
-	"reflect"
 )
 
 // Config customize how the API should behave.
@@ -63,7 +63,6 @@ var ConfigFastest = Config{
 	ObjectFieldMustBeSimpleString: true, // do not unescape object field
 }.Froze()
 
-
 type frozenConfig struct {
 	configBeforeFrozen            Config
 	sortMapKeys                   bool