[Atomics] Remove Atomics code stubs; use TF ops

src/compiler/raw-machine-assembler.h

 // 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.
 
 #ifndef V8_COMPILER_RAW_MACHINE_ASSEMBLER_H_
 #define V8_COMPILER_RAW_MACHINE_ASSEMBLER_H_
 
 #include "src/assembler.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/graph.h"
@@ skipping 115 matching lines @@
   Node* Store(MachineRepresentation rep, Node* base, Node* value,
               WriteBarrierKind write_barrier) {
     return Store(rep, base, IntPtrConstant(0), value, write_barrier);
   }
   Node* Store(MachineRepresentation rep, Node* base, Node* index, Node* value,
               WriteBarrierKind write_barrier) {
     return AddNode(machine()->Store(StoreRepresentation(rep, write_barrier)),
                    base, index, value);
   }
 
+  // Atomic memory operations.
+  Node* AtomicLoad(MachineType rep, Node* base, Node* index) {
+    return AddNode(machine()->AtomicLoad(rep), base, index);
+  }
+
   // Arithmetic Operations.
   Node* WordAnd(Node* a, Node* b) {
     return AddNode(machine()->WordAnd(), a, b);
   }
   Node* WordOr(Node* a, Node* b) { return AddNode(machine()->WordOr(), a, b); }
   Node* WordXor(Node* a, Node* b) {
     return AddNode(machine()->WordXor(), a, b);
   }
   Node* WordShl(Node* a, Node* b) {
     return AddNode(machine()->WordShl(), a, b);
@@ skipping 601 matching lines @@
   bool deferred_;
   friend class RawMachineAssembler;
   DISALLOW_COPY_AND_ASSIGN(RawMachineLabel);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_RAW_MACHINE_ASSEMBLER_H_