[turbofan] cleanup InstructionOperand a little

src/compiler/gap-resolver.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/gap-resolver.h"
 
 #include <algorithm>
 #include <functional>
 #include <set>
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 typedef ZoneList<MoveOperands>::iterator op_iterator;
 
 #ifdef ENABLE_SLOW_DCHECKS
-// TODO(svenpanne) Brush up InstructionOperand with comparison?
 struct InstructionOperandComparator {
   bool operator()(const InstructionOperand* x,
                   const InstructionOperand* y) const {
-    return (x->kind() < y->kind()) ||
-           (x->kind() == y->kind() && x->index() < y->index());
+    return *x < *y;
   }
 };
 #endif
 
 // No operand should be the destination for more than one move.
 static void VerifyMovesAreInjective(ZoneList<MoveOperands>* moves) {
 #ifdef ENABLE_SLOW_DCHECKS
   std::set<InstructionOperand*, InstructionOperandComparator> seen;
   for (op_iterator i = moves->begin(); i != moves->end(); ++i) {
     SLOW_DCHECK(seen.find(i->destination()) == seen.end());
@@ skipping 93 matching lines @@
     if (other->Blocks(source)) {
       other->set_source(destination);
     } else if (other->Blocks(destination)) {
       other->set_source(source);
     }
   }
 }
 }
 }
 }  // namespace v8::internal::compiler