[Atomics] Remove Atomics code stubs; use TF ops

src/code-factory.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/code-factory.h"
 
 #include "src/bootstrapper.h"
 #include "src/ic/ic.h"
 
 namespace v8 {
@@ skipping 545 matching lines @@
 
 
 // static
 Callable CodeFactory::InterpreterCEntry(Isolate* isolate, int result_size) {
   // Note: If we ever use fpregs in the interpreter then we will need to
   // save fpregs too.
   CEntryStub stub(isolate, result_size, kDontSaveFPRegs, kArgvInRegister);
   return Callable(stub.GetCode(), InterpreterCEntryDescriptor(isolate));
 }
 
-Callable CodeFactory::AtomicsLoad(Isolate* isolate) {
-  AtomicsLoadStub stub(isolate);
-  return Callable(stub.GetCode(), AtomicsLoadDescriptor(isolate));
-}
-
 }  // namespace internal
 }  // namespace v8