string_decoder: refactor to use more primordials

PR-URL: https://github.com/nodejs/node/pull/36358
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

lib/string_decoder.js

@@ -25,6 +25,7 @@ const {
   ArrayBufferIsView,
   ObjectDefineProperties,
   Symbol,
+  TypedArrayPrototypeSubarray,
 } = primordials;
 
 const { Buffer } = require('buffer');
@@ -104,8 +105,9 @@ ObjectDefineProperties(StringDecoder.prototype, {
     configurable: true,
     enumerable: true,
     get() {
-      return this[kNativeDecoder].subarray(kIncompleteCharactersStart,
-                                           kIncompleteCharactersEnd);
+      return TypedArrayPrototypeSubarray(this[kNativeDecoder],
+                                         kIncompleteCharactersStart,
+                                         kIncompleteCharactersEnd);
     }
   },
   lastNeed: {