VM: Link native calls lazily.

runtime/vm/code_patcher.h

 // Copyright (c) 2012, 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.
 // Class for patching compiled code.
 
 #ifndef VM_CODE_PATCHER_H_
 #define VM_CODE_PATCHER_H_
 
 #include "vm/allocation.h"
+#include "vm/native_entry.h"
 
 namespace dart {
 
 // Forward declaration.
 class Array;
 class Code;
 class ExternalLabel;
 class Function;
 class ICData;
 class RawArray;
@@ skipping 61 matching lines @@
   static RawFunction* GetUnoptimizedStaticCallAt(uword return_address,
                                                  const Code& code,
                                                  ICData* ic_data);
 
   static intptr_t InstanceCallSizeInBytes();
 
   static void InsertCallAt(uword start, uword target);
 
   static RawObject* GetEdgeCounterAt(uword pc, const Code& code);
 
-  static int32_t GetPoolOffsetAt(uword return_address);
-  static void SetPoolOffsetAt(uword return_address, int32_t offset);
   static void PatchPoolPointerCallAt(uword return_address,
                                      const Code& code,
                                      uword new_target);
+
+  static uword GetNativeCallAt(uword return_address,
+                               const Code& code,
+                               NativeFunction* target);
+
+  static void PatchNativeCallAt(uword return_address,
+                                const Code& code,
+                                NativeFunction target,
+                                const Code& trampoline);
 };
 
 }  // namespace dart
 
 #endif  // VM_CODE_PATCHER_H_