Basic TurboFan support for rest arguments.

test/cctest/compiler/test-run-jsobjects.cc

Index: test/cctest/compiler/test-run-jsobjects.cc
diff --git a/test/cctest/compiler/test-run-jsobjects.cc b/test/cctest/compiler/test-run-jsobjects.cc
index 9ba5064b66f5be255fa32e5e104d0da1c7bec08a..4bf10ca8feb781758e1a8b9990c11ef35a3e77c6 100644
--- a/test/cctest/compiler/test-run-jsobjects.cc
+++ b/test/cctest/compiler/test-run-jsobjects.cc
@@ -35,9 +35,6 @@ TEST(ArgumentsUnmapped) {
 
 
 TEST(ArgumentsRest) {
-  // TODO(mvstanton): restore this test when Turbofan again supports rest args.
-  // (soon).
-  return;
   FunctionTester T("(function(a, ...args) { return args; })");
 
   Handle<Object> arguments;