[turbofan] Make sure Operator is really immutable.

src/compiler/graph-replay.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/graph-replay.h"
 
 #include "src/compiler/common-operator.h"
 #include "src/compiler/graph.h"
 #include "src/compiler/graph-inl.h"
 #include "src/compiler/node.h"
@@ skipping 22 matching lines @@
   PrintF("); USE(n%d);\n", node->id());
   return GenericGraphVisit::CONTINUE;
 }
 
 
 void GraphReplayPrinter::PostEdge(Node* from, int index, Node* to) {
   PrintF("  n%d->ReplaceInput(%d, n%d);\n", from->id(), index, to->id());
 }
 
 
-void GraphReplayPrinter::PrintReplayOpCreator(Operator* op) {
+void GraphReplayPrinter::PrintReplayOpCreator(const Operator* op) {
   IrOpcode::Value opcode = static_cast<IrOpcode::Value>(op->opcode());
   const char* builder =
       IrOpcode::IsCommonOpcode(opcode) ? "common_builder" : "js_builder";
   const char* mnemonic = IrOpcode::IsCommonOpcode(opcode)
                              ? IrOpcode::Mnemonic(opcode)
                              : IrOpcode::Mnemonic(opcode) + 2;
   PrintF("  op = %s.%s(", builder, mnemonic);
   switch (opcode) {
     case IrOpcode::kParameter:
     case IrOpcode::kNumberConstant:
@@ skipping 18 matching lines @@
     default:
       break;
   }
   PrintF(");\n");
 }
 
 #endif  // DEBUG
 }
 }
 }  // namespace v8::internal::compiler