Use proper write barrier mode when creating rest parameters.

src/runtime/runtime-scopes.cc

Index: src/runtime/runtime-scopes.cc
diff --git a/src/runtime/runtime-scopes.cc b/src/runtime/runtime-scopes.cc
index 0bdbe2e44172da6f9a0efd3bac703ba0aafc8a5e..8b1f27a18f2390743176dab4372a7c9e33424ee1 100644
--- a/src/runtime/runtime-scopes.cc
+++ b/src/runtime/runtime-scopes.cc
@@ -558,7 +558,7 @@ RUNTIME_FUNCTION(Runtime_NewRestParameter) {
   {
     DisallowHeapAllocation no_gc;
     FixedArray* elements = FixedArray::cast(result->elements());
-    WriteBarrierMode mode = result->GetWriteBarrierMode(no_gc);
+    WriteBarrierMode mode = elements->GetWriteBarrierMode(no_gc);
     for (int i = 0; i < num_elements; i++) {
       elements->set(i, *arguments[i + start_index], mode);
     }