Add tests for Subclassing the built-in DataView Objects

test/language/subclassing/DataView/regular-subclassing.js

@@ -0,0 +1,28 @@
+// Copyright (C) 2016 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+es6id: 24.2.2
+description: Subclassing the DataView object
+info: >
+  24.2.2 The DataView Constructor
+
+  ...
+
+  The DataView constructor is designed to be subclassable. It may be used as the
+  value of an extends clause of a class definition. Subclass constructors that
+  intend to inherit the specified DataView behaviour must include a super call
+  to the DataView constructor to create and initialize subclass instances with
+  the internal state necessary to support the DataView.prototype built-in
+  methods.
+---*/
+
+class DV extends DataView {}
+
+var buffer = new ArrayBuffer(1);
+
+var dv = new DV(buffer);
+assert.sameValue(dv.buffer, buffer);
+
+assert.throws(TypeError, function() {
+  new DV();
+});

test/language/subclassing/DataView/super-must-be-called.js

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+// Copyright (C) 2016 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+es6id: 24.2.2
+description: Super need to be called to initialize internals
+info: >
+  24.2.2 The DataView Constructor
+
+  ...
+
+  The DataView constructor is designed to be subclassable. It may be used as the
+  value of an extends clause of a class definition. Subclass constructors that
+  intend to inherit the specified DataView behaviour must include a super call
+  to the DataView constructor to create and initialize subclass instances with
+  the internal state necessary to support the DataView.prototype built-in
+  methods.
+---*/
+
+class DV1 extends DataView {
+  constructor() {}
+}
+
+var buffer = new ArrayBuffer(1);
+
+assert.throws(ReferenceError, function() {
+  new DV1(buffer);
+});
+
+class DV2 extends DataView {
+  constructor(length) {
+    super(length);
+  }
+}
+
+new DV2(buffer);