Fix Array.prototype.sort on proxies.

test/mjsunit/array-sort.js

Index: test/mjsunit/array-sort.js
diff --git a/test/mjsunit/array-sort.js b/test/mjsunit/array-sort.js
index 36608f5e142e455cb86659d2c8814007cb1fc579..beb8b95b014bb402ce7e7fe715b333489e4d913c 100644
--- a/test/mjsunit/array-sort.js
+++ b/test/mjsunit/array-sort.js
@@ -464,3 +464,9 @@ function TestSortToObject() {
   assertEquals(0, Number(Array.prototype.sort.call(0)));
 }
 TestSortToObject();
+
+function TestSortOnProxy() {
+  var p = new Proxy([2,1,3], {});
+  assertEquals([1,2,3], p.sort());
+}
+TestSortOnProxy();