Introduce the SetFp function in StackHandler

src/x64/frames-x64.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 108 matching lines @@
   // FP-relative.
   static const int kCodeOffset = StandardFrameConstants::kExpressionsOffset;
 };
 
 
 inline Object* JavaScriptFrame::function_slot_object() const {
   const int offset = JavaScriptFrameConstants::kFunctionOffset;
   return Memory::Object_at(fp() + offset);
 }
 
+
+inline void StackHandler::SetFp(Address slot, Address fp) {
+  Memory::Address_at(slot) = fp;
+}
+
+
 } }  // namespace v8::internal
 
 #endif  // V8_X64_FRAMES_X64_H_