Make sure that Array.of works when subclassed.

es6-shim.js

@@ -740,7 +740,7 @@
     },
 
     of: function of() {
-      return Array.from(arguments);
+      return Array.from.call(this, arguments);
     }
   };
   defineProperties(Array, ArrayShims);
@@ -972,7 +972,8 @@
   if (Array.prototype.values && Array.prototype.values.name !== 'values') {
     var originalArrayPrototypeValues = Array.prototype.values;
     defineProperty(Array.prototype, 'values', function values() { return originalArrayPrototypeValues.call(this); }, true);
-    Array.prototype[$iterator$] = Array.prototype.values;
+    defineProperty(Array.prototype, $iterator$, Array.prototype.values, true);
+    Value.preserveToString(Array.prototype.values, originalArrayPrototypeValues);
   }
   defineProperties(Array.prototype, ArrayPrototypeShims);
 

test/array.js

@@ -259,6 +259,20 @@ var runArrayTests = function () {
       it('should create correct array from arguments', function () {
         expect(Array.of(1, null, undefined)).to.eql([1, null, undefined]);
       });
+
+      it('should work with other constructors', function () {
+        var Foo = function (length) {
+          this.args = Array.prototype.slice.call(arguments, 1);
+          this.length = length;
+        };
+        var args = ['a', 'b', 'c'];
+        var expected = new Foo(args.length);
+        args.forEach(function (arg, index) {
+          expected[index] = arg;
+        });
+        expect(Array.of.apply(Foo, args)).to.eql(expected);
+      });
+
     });
 
     describe('Array#copyWithin', function () {