Fix native argument handling

runtime/lib/isolate.cc

Index: runtime/lib/isolate.cc
===================================================================
--- runtime/lib/isolate.cc	(revision 14922)
+++ runtime/lib/isolate.cc	(working copy)
@@ -113,7 +113,8 @@
 
 
 DEFINE_NATIVE_ENTRY(ReceivePortImpl_factory, 1) {
-  ASSERT(AbstractTypeArguments::CheckedHandle(arguments->At(0)).IsNull());
+  ASSERT(AbstractTypeArguments::CheckedHandle(
+      arguments->NativeArgAt(0)).IsNull());
   intptr_t port_id =
       PortMap::CreatePort(arguments->isolate()->message_handler());
   const Object& port = Object::Handle(ReceivePortCreate(port_id));
@@ -125,17 +126,17 @@
 
 
 DEFINE_NATIVE_ENTRY(ReceivePortImpl_closeInternal, 1) {
-  GET_NATIVE_ARGUMENT(Smi, id, arguments->At(0));
+  GET_NATIVE_ARGUMENT(Smi, id, arguments->NativeArgAt(0));
   PortMap::ClosePort(id.Value());
   return Object::null();
 }
 
 
 DEFINE_NATIVE_ENTRY(SendPortImpl_sendInternal_, 3) {
-  GET_NATIVE_ARGUMENT(Smi, send_id, arguments->At(0));
-  GET_NATIVE_ARGUMENT(Smi, reply_id, arguments->At(1));
+  GET_NATIVE_ARGUMENT(Smi, send_id, arguments->NativeArgAt(0));
+  GET_NATIVE_ARGUMENT(Smi, reply_id, arguments->NativeArgAt(1));
   // TODO(iposva): Allow for arbitrary messages to be sent.
-  GET_NATIVE_ARGUMENT(Instance, obj, arguments->At(2));
+  GET_NATIVE_ARGUMENT(Instance, obj, arguments->NativeArgAt(2));
 
   uint8_t* data = NULL;
   MessageWriter writer(&data, &allocator);
@@ -398,7 +399,7 @@
 
 
 DEFINE_NATIVE_ENTRY(isolate_spawnFunction, 1) {
-  GET_NATIVE_ARGUMENT(Instance, closure, arguments->At(0));
+  GET_NATIVE_ARGUMENT(Instance, closure, arguments->NativeArgAt(0));
   bool throw_exception = false;
   Function& func = Function::Handle();
   if (closure.IsClosure()) {
@@ -427,7 +428,7 @@
 
 
 DEFINE_NATIVE_ENTRY(isolate_spawnUri, 1) {
-  GET_NATIVE_ARGUMENT(String, uri, arguments->At(0));
+  GET_NATIVE_ARGUMENT(String, uri, arguments->NativeArgAt(0));
 
   // Canonicalize the uri with respect to the current isolate.
   char* error = NULL;