Revert of [Atomics] Remove Atomics code stubs; use TF ops

src/compiler/verifier.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/compiler/verifier.h"
 
 #include <algorithm>
 #include <deque>
 #include <queue>
 #include <sstream>
@@ skipping 976 matching lines @@
     case IrOpcode::kInt32PairSub:
     case IrOpcode::kInt32PairMul:
     case IrOpcode::kWord32PairShl:
     case IrOpcode::kWord32PairShr:
     case IrOpcode::kWord32PairSar:
     case IrOpcode::kLoadStackPointer:
     case IrOpcode::kLoadFramePointer:
     case IrOpcode::kLoadParentFramePointer:
     case IrOpcode::kCheckedLoad:
     case IrOpcode::kCheckedStore:
-    case IrOpcode::kAtomicLoad:
       // TODO(rossberg): Check.
       break;
   }
 }  // NOLINT(readability/fn_size)
 
 
 void Verifier::Run(Graph* graph, Typing typing) {
   CHECK_NOT_NULL(graph->start());
   CHECK_NOT_NULL(graph->end());
   Zone zone(graph->zone()->allocator());
@@ skipping 310 matching lines @@
          replacement->op()->EffectOutputCount() > 0);
   DCHECK(!NodeProperties::IsFrameStateEdge(edge) ||
          replacement->opcode() == IrOpcode::kFrameState);
 }
 
 #endif  // DEBUG
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8