Remove RecordWriteStub from X64 and ARM platforms.

src/x64/codegen-x64.cc

Index: src/x64/codegen-x64.cc
===================================================================
--- src/x64/codegen-x64.cc	(revision 6127)
+++ src/x64/codegen-x64.cc	(working copy)
@@ -6813,12 +6813,8 @@
   // (or them and test against Smi mask.)
 
   __ movq(tmp2.reg(), tmp1.reg());
-  RecordWriteStub recordWrite1(tmp2.reg(), index1.reg(), object.reg());
-  __ CallStub(&recordWrite1);
-
-  RecordWriteStub recordWrite2(tmp1.reg(), index2.reg(), object.reg());
-  __ CallStub(&recordWrite2);
-
+  __ RecordWriteHelper(tmp1.reg(), index1.reg(), object.reg());
+  __ RecordWriteHelper(tmp2.reg(), index2.reg(), object.reg());
   __ bind(&done);
 
   deferred->BindExit();
@@ -8812,11 +8808,6 @@
 
 #undef __
 
-void RecordWriteStub::Generate(MacroAssembler* masm) {
-  masm->RecordWriteHelper(object_, addr_, scratch_);
-  masm->ret(0);
-}
-
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64