[turbofan] Do Smi comparison without untagging when lowering SpeculativeNumber(Compare).

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 220 matching lines @@
 
   // Changes representation from {output_type} to {use_rep}. The {truncation}
   // parameter is only used for sanity checking - if the changer cannot figure
   // out signedness for the word32->float64 conversion, then we check that the
   // uses truncate to word32 (so they do not care about signedness).
   Node* GetRepresentationFor(Node* node, MachineRepresentation output_rep,
                              Type* output_type, Node* use_node,
                              UseInfo use_info);
   const Operator* Int32OperatorFor(IrOpcode::Value opcode);
   const Operator* Int32OverflowOperatorFor(IrOpcode::Value opcode);
+  const Operator* TaggedSignedOperatorFor(IrOpcode::Value opcode);
   const Operator* Uint32OperatorFor(IrOpcode::Value opcode);
   const Operator* Uint32OverflowOperatorFor(IrOpcode::Value opcode);
   const Operator* Float64OperatorFor(IrOpcode::Value opcode);
 
   MachineType TypeForBasePointer(const FieldAccess& access) {
     return access.tag() != 0 ? MachineType::AnyTagged()
                              : MachineType::Pointer();
   }
 
   MachineType TypeForBasePointer(const ElementAccess& access) {
@@ skipping 53 matching lines @@
   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_