[turbofan] Remove dead code from representation changer.

src/compiler/representation-change.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_REPRESENTATION_CHANGE_H_
 #define V8_COMPILER_REPRESENTATION_CHANGE_H_
 
 #include "src/compiler/js-graph.h"
 #include "src/compiler/simplified-operator.h"
 
@@ skipping 204 matching lines @@
                                     MachineRepresentation output_rep,
                                     Type* output_type, Node* use_node,
                                     UseInfo use_info);
   Node* GetWord32RepresentationFor(Node* node, MachineRepresentation output_rep,
                                    Type* output_type, Node* use_node,
                                    UseInfo use_info);
   Node* GetBitRepresentationFor(Node* node, MachineRepresentation output_rep,
                                 Type* output_type);
   Node* GetWord64RepresentationFor(Node* node, MachineRepresentation output_rep,
                                    Type* output_type);
-  Node* GetCheckedWord32RepresentationFor(Node* node,
-                                          MachineRepresentation output_rep,
-                                          Type* output_type, Node* use_node,
-                                          Truncation truncation,
-                                          TypeCheckKind check);
   Node* TypeError(Node* node, MachineRepresentation output_rep,
                   Type* output_type, MachineRepresentation use);
   Node* MakeTruncatedInt32Constant(double value);
   Node* InsertChangeFloat32ToFloat64(Node* node);
   Node* InsertChangeFloat64ToInt32(Node* node);
   Node* InsertChangeFloat64ToUint32(Node* node);
   Node* InsertChangeTaggedSignedToInt32(Node* node);
   Node* InsertChangeTaggedToFloat64(Node* node);
 
   Node* InsertConversion(Node* node, const Operator* op, Node* use_node);
 
   JSGraph* jsgraph() const { return jsgraph_; }
   Isolate* isolate() const { return isolate_; }
   Factory* factory() const { return isolate()->factory(); }
   SimplifiedOperatorBuilder* simplified() { return jsgraph()->simplified(); }
   MachineOperatorBuilder* machine() { return jsgraph()->machine(); }
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_REPRESENTATION_CHANGE_H_