Our JavaScriptFrame::function_slot_object is arch independent.

src/x87/frames-x87.h

Index: src/x87/frames-x87.h
diff --git a/src/x87/frames-x87.h b/src/x87/frames-x87.h
index 78209258d62c9c5c2441709c971384f0a43a2c22..c9e75e83ea60a4d06d9a9681a77e9da42efa3f0b 100644
--- a/src/x87/frames-x87.h
+++ b/src/x87/frames-x87.h
@@ -79,12 +79,6 @@ class JavaScriptFrameConstants : public AllStatic {
 };
 
 
-inline Object* JavaScriptFrame::function_slot_object() const {
-  const int offset = JavaScriptFrameConstants::kFunctionOffset;
-  return Memory::Object_at(fp() + offset);
-}
-
-
 } }  // namespace v8::internal
 
 #endif  // V8_X87_FRAMES_X87_H_