Rename & improve "length" test

test/built-ins/Object/getOwnPropertyDescriptor/15.2.3.3-0-2.js

@@ -1,11 +0,0 @@
-// Copyright (c) 2012 Ecma International.  All rights reserved.
-// This code is governed by the BSD license found in the LICENSE file.
-
-/*---
-es5id: 15.2.3.3-0-2
-description: >
-    Object.getOwnPropertyDescriptor must exist as a function taking 2
-    parameters
----*/
-
-assert.sameValue(Object.getOwnPropertyDescriptor.length, 2, 'Object.getOwnPropertyDescriptor.length');

test/built-ins/Object/getOwnPropertyDescriptor/length.js

@@ -0,0 +1,27 @@
+// Copyright (C) 2012 Ecma International. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-object.getownpropertydescriptor
+description: >
+  Object.getOwnPropertyDescriptor.length is 2.
+info: |
+  Object.getOwnPropertyDescriptor ( O, P )
+
+  ECMAScript Standard Built-in Objects
+
+  Every built-in function object, including constructors, has a "length" property whose
+  value is an integer. Unless otherwise specified, this value is equal to the largest
+  number of named arguments shown in the subclause headings for the function description.
+
+  Unless otherwise specified, the "length" property of a built-in function object has
+  the attributes { [[Writable]]: false, [[Enumerable]]: false, [[Configurable]]: true }.
+includes: [propertyHelper.js]
+---*/
+
+verifyProperty(Object.getOwnPropertyDescriptor, "length", {
+  value: 2,
+  writable: false,
+  enumerable: false,
+  configurable: true,
+});