[turbofan] Next step towards shared operators.

src/compiler/js-graph.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/js-graph.h"
 #include "src/compiler/node-properties-inl.h"
 #include "src/compiler/typer.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 Node* JSGraph::ImmovableHeapConstant(Handle<Object> object) {
   Unique<Object> unique = Unique<Object>::CreateImmovable(object);
   return NewNode(common()->HeapConstant(unique));
 }
 
 
-Node* JSGraph::NewNode(Operator* op) {
+Node* JSGraph::NewNode(const Operator* op) {
   Node* node = graph()->NewNode(op);
   typer_->Init(node);
   return node;
 }
 
 
 Node* JSGraph::CEntryStubConstant() {
   if (!c_entry_stub_constant_.is_set()) {
     c_entry_stub_constant_.set(
         ImmovableHeapConstant(CEntryStub(isolate(), 1).GetCode()));
@@ skipping 147 matching lines @@
 Node* JSGraph::ExternalConstant(ExternalReference reference) {
   Node** loc = cache_.FindExternalConstant(reference);
   if (*loc == NULL) {
     *loc = NewNode(common()->ExternalConstant(reference));
   }
   return *loc;
 }
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8