Support deferred library prefix syntax

runtime/lib/object.cc

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/bootstrap_natives.h"
 
 #include "lib/invocation_mirror.h"
 #include "vm/exceptions.h"
 #include "vm/heap.h"
 #include "vm/native_entry.h"
@@ skipping 212 matching lines @@
   return instance.raw();
 }
 
 
 DEFINE_NATIVE_ENTRY(AbstractType_toString, 1) {
   const AbstractType& type =
       AbstractType::CheckedHandle(arguments->NativeArgAt(0));
   return type.UserVisibleName();
 }
 
+
+DEFINE_NATIVE_ENTRY(LibraryPrefix_load, 1) {
+  const LibraryPrefix& prefix =
+      LibraryPrefix::CheckedHandle(arguments->NativeArgAt(0));
+  prefix.LoadLibrary();
+  return Bool::Get(true).raw();
+}
+
 }  // namespace dart