VM: Set breakpoints on x64 and arm64 without patching code.

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"
 
@@ skipping 72 matching lines @@
                                                  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);
 };
 
 }  // namespace dart
 
 #endif  // VM_CODE_PATCHER_H_