Remove RecordWriteStub from X64 and ARM platforms.

src/arm/code-stubs-arm.h

Index: src/arm/code-stubs-arm.h
===================================================================
--- src/arm/code-stubs-arm.h	(revision 6127)
+++ src/arm/code-stubs-arm.h	(working copy)
@@ -437,43 +437,6 @@
 };
 
 
-class RecordWriteStub : public CodeStub {
- public:
-  RecordWriteStub(Register object, Register offset, Register scratch)
-      : object_(object), offset_(offset), scratch_(scratch) { }
-
-  void Generate(MacroAssembler* masm);
-
- private:
-  Register object_;
-  Register offset_;
-  Register scratch_;
-
-  // Minor key encoding in 12 bits. 4 bits for each of the three
-  // registers (object, offset and scratch) OOOOAAAASSSS.
-  class ScratchBits: public BitField<uint32_t, 0, 4> {};
-  class OffsetBits: public BitField<uint32_t, 4, 4> {};
-  class ObjectBits: public BitField<uint32_t, 8, 4> {};
-
-  Major MajorKey() { return RecordWrite; }
-
-  int MinorKey() {
-    // Encode the registers.
-    return ObjectBits::encode(object_.code()) |
-           OffsetBits::encode(offset_.code()) |
-           ScratchBits::encode(scratch_.code());
-  }
-
-#ifdef DEBUG
-  void Print() {
-    PrintF("RecordWriteStub (object reg %d), (offset reg %d),"
-           " (scratch reg %d)\n",
-           object_.code(), offset_.code(), scratch_.code());
-  }
-#endif
-};
-
-
 // Enter C code from generated RegExp code in a way that allows
 // the C code to fix the return address in case of a GC.
 // Currently only needed on ARM.