Add TypedArrayConstructors test

test/built-ins/TypedArrayConstructors/ctors/object-arg/iterator-is-null-as-array-like.js

@@ -0,0 +1,42 @@
+// Copyright (C) 2020 Alexey Shvayka. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-typedarray-object
+description: >
+  If object's @@iterator is `null`, it is considered an array-like object.
+info: |
+  TypedArray ( object )
+
+  This description applies only if the TypedArray function is called with at
+  least one argument and the Type of the first argument is Object and that
+  object does not have either a [[TypedArrayName]] or an [[ArrayBufferData]]
+  internal slot.
+
+  [...]
+  5. Let usingIterator be ? GetMethod(object, @@iterator).
+  6. If usingIterator is not undefined, then
+    [...]
+  7. NOTE: object is not an Iterable so assume it is already an array-like object.
+  [...]
+
+  GetMethod ( V, P )
+
+  [...]
+  2. Let func be ? GetV(V, P).
+  3. If func is either undefined or null, return undefined.
+includes: [testTypedArray.js]
+features: [Symbol.iterator, TypedArray]
+---*/
+
+var obj = {length: 2, 0: 1, 1: 2};
+obj[Symbol.iterator] = null;
+
+testWithTypedArrayConstructors(function(TypedArray) {
+  var typedArray = new TypedArray(obj);
+
+  assert(typedArray instanceof TypedArray);
+  assert.sameValue(typedArray.length, 2);
+  assert.sameValue(typedArray[0], 1);
+  assert.sameValue(typedArray[1], 2);
+});