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

src/compiler/instruction-selector.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/instruction-selector.h"
 
 #include <limits>
 
 #include "src/base/adapters.h"
 #include "src/compiler/instruction-selector-impl.h"
@@ skipping 1162 matching lines @@
       MarkAsWord32(NodeProperties::FindProjection(node, 1));
       return VisitWord32PairShl(node);
     case IrOpcode::kWord32PairShr:
       MarkAsWord32(NodeProperties::FindProjection(node, 0));
       MarkAsWord32(NodeProperties::FindProjection(node, 1));
       return VisitWord32PairShr(node);
     case IrOpcode::kWord32PairSar:
       MarkAsWord32(NodeProperties::FindProjection(node, 0));
       MarkAsWord32(NodeProperties::FindProjection(node, 1));
       return VisitWord32PairSar(node);
-    case IrOpcode::kAtomicLoad: {
-      LoadRepresentation type = LoadRepresentationOf(node->op());
-      MarkAsRepresentation(type.representation(), node);
-      return VisitAtomicLoad(node);
-    }
     default:
       V8_Fatal(__FILE__, __LINE__, "Unexpected operator #%d:%s @ node #%d",
                node->opcode(), node->op()->mnemonic(), node->id());
       break;
   }
 }
 
 
 void InstructionSelector::VisitLoadStackPointer(Node* node) {
   OperandGenerator g(this);
@@ skipping 609 matching lines @@
   return new (instruction_zone()) FrameStateDescriptor(
       instruction_zone(), state_info.type(), state_info.bailout_id(),
       state_info.state_combine(), parameters, locals, stack,
       state_info.shared_info(), outer_state);
 }
 
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8