[turbofan] Introduce dedicated BitcastWordToTagged machine operator.

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 957 matching lines @@
     case IrOpcode::kRoundInt64ToFloat64:
     case IrOpcode::kRoundUint32ToFloat32:
     case IrOpcode::kRoundUint64ToFloat64:
     case IrOpcode::kRoundUint64ToFloat32:
     case IrOpcode::kTruncateFloat64ToFloat32:
     case IrOpcode::kTruncateFloat64ToInt32:
     case IrOpcode::kBitcastFloat32ToInt32:
     case IrOpcode::kBitcastFloat64ToInt64:
     case IrOpcode::kBitcastInt32ToFloat32:
     case IrOpcode::kBitcastInt64ToFloat64:
+    case IrOpcode::kBitcastWordToTagged:
     case IrOpcode::kChangeInt32ToInt64:
     case IrOpcode::kChangeUint32ToUint64:
     case IrOpcode::kChangeInt32ToFloat64:
     case IrOpcode::kChangeUint32ToFloat64:
     case IrOpcode::kChangeFloat32ToFloat64:
     case IrOpcode::kChangeFloat64ToInt32:
     case IrOpcode::kChangeFloat64ToUint32:
     case IrOpcode::kTruncateFloat64ToUint32:
     case IrOpcode::kTruncateFloat32ToInt32:
     case IrOpcode::kTruncateFloat32ToUint32:
@@ skipping 340 matching lines @@
          replacement->op()->EffectOutputCount() > 0);
   DCHECK(!NodeProperties::IsFrameStateEdge(edge) ||
          replacement->opcode() == IrOpcode::kFrameState);
 }
 
 #endif  // DEBUG
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8