Construct instances of base class from TypedArray.prototype.subarray

test/mjsunit/es6/legacy-subclassing.js

Index: test/mjsunit/es6/legacy-subclassing.js
diff --git a/test/mjsunit/es6/legacy-subclassing.js b/test/mjsunit/es6/legacy-subclassing.js
index 73b684f99461237f55446e4340a61063effd6b71..dbf666d07c9d060d52e3de29fb57e17def7fbd5f 100644
--- a/test/mjsunit/es6/legacy-subclassing.js
+++ b/test/mjsunit/es6/legacy-subclassing.js
@@ -33,3 +33,6 @@ class MyPromise extends Promise { }
 let myPromise = new MyPromise(() => {});
 assertEquals(MyPromise, myPromise.constructor);
 assertEquals(MyPromise, myPromise.then().constructor);
+
+// However, subarray instantiates members of the parent class
+assertEquals(Uint8Array, myTypedArray.subarray(1).constructor);