Cleanup access to Instruction's fields (especially deopt_id_).

runtime/vm/flow_graph_optimizer.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/flow_graph_optimizer.h"
 
 #include "vm/bit_vector.h"
 #include "vm/cha.h"
 #include "vm/cpu.h"
 #include "vm/dart_entry.h"
@@ skipping 4985 matching lines @@
   // Move the instruction out of the loop.
   current->RemoveEnvironment();
   if (it != NULL) {
     it->RemoveCurrentFromGraph();
   } else {
     current->RemoveFromGraph();
   }
   GotoInstr* last = pre_header->last_instruction()->AsGoto();
   // Using kind kEffect will not assign a fresh ssa temporary index.
   flow_graph()->InsertBefore(last, current, last->env(), FlowGraph::kEffect);
-  current->deopt_id_ = last->GetDeoptId();
+  current->CopyDeoptIdFrom(*last);
 }
 
 
 void LICM::TrySpecializeSmiPhi(PhiInstr* phi,
                                BlockEntryInstr* header,
                                BlockEntryInstr* pre_header) {
   if (phi->Type()->ToCid() == kSmiCid) {
     return;
   }
 
@@ skipping 4237 matching lines @@
         BranchInstr* new_branch =
             CloneBranch(isolate, branch, new_left, new_right);
         if (branch->env() == NULL) {
           new_branch->InheritDeoptTarget(isolate, old_goto);
         } else {
           // Take the environment from the branch if it has one.
           new_branch->InheritDeoptTarget(isolate, branch);
           // InheritDeoptTarget gave the new branch's comparison the same
           // deopt id that it gave the new branch.  The id should be the
           // deopt id of the original comparison.
-          new_branch->comparison()->SetDeoptId(comparison->GetDeoptId());
+          new_branch->comparison()->SetDeoptId(*comparison);
           // The phi can be used in the branch's environment.  Rename such
           // uses.
           for (Environment::DeepIterator it(new_branch->env());
                !it.Done();
                it.Advance()) {
             Value* use = it.CurrentValue();
             if (use->definition() == phi) {
               Definition* replacement = phi->InputAt(i)->definition();
               use->RemoveFromUseList();
               use->set_definition(replacement);
@@ skipping 803 matching lines @@
 
   // Insert materializations at environment uses.
   for (intptr_t i = 0; i < exits_collector_.exits().length(); i++) {
     CreateMaterializationAt(
         exits_collector_.exits()[i], alloc, *slots);
   }
 }
 
 
 }  // namespace dart