[turbofan] Correctly use bit_cast instead of static_cast.

src/compiler/simplified-operator-reducer.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_SIMPLIFIED_OPERATOR_REDUCER_H_
 #define V8_COMPILER_SIMPLIFIED_OPERATOR_REDUCER_H_
 
 #include "src/compiler/graph-reducer.h"
 
 namespace v8 {
@@ skipping 14 matching lines @@
       : jsgraph_(jsgraph), machine_(machine) {}
   virtual ~SimplifiedOperatorReducer();
 
   virtual Reduction Reduce(Node* node) OVERRIDE;
 
  private:
   Reduction Change(Node* node, Operator* op, Node* a);
   Reduction ReplaceFloat64(double value);
   Reduction ReplaceInt32(int32_t value);
   Reduction ReplaceUint32(uint32_t value) {
-    return ReplaceInt32(static_cast<int32_t>(value));
+    return ReplaceInt32(bit_cast<int32_t>(value));
   }
   Reduction ReplaceNumber(double value);
   Reduction ReplaceNumber(int32_t value);
 
   Graph* graph() const;
   Factory* factory() const;
   JSGraph* jsgraph() const { return jsgraph_; }
   MachineOperatorBuilder* machine() const { return machine_; }
 
   JSGraph* jsgraph_;
   MachineOperatorBuilder* machine_;
 
   DISALLOW_COPY_AND_ASSIGN(SimplifiedOperatorReducer);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_SIMPLIFIED_OPERATOR_REDUCER_H_