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

runtime/vm/flow_graph_range_analysis.cc

 // Copyright (c) 2014, 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_range_analysis.h"
 
 #include "vm/bit_vector.h"
 #include "vm/il_printer.h"
 
 namespace dart {
@@ skipping 940 matching lines @@
     return NULL;
   }
 
   void EmitTo(BlockEntryInstr* block, Instruction* instr) {
     GotoInstr* last = block->last_instruction()->AsGoto();
     flow_graph_->InsertBefore(last,
                               instr,
                               last->env(),
                               instr->IsDefinition() ? FlowGraph::kValue
                                                     : FlowGraph::kEffect);
-    instr->deopt_id_ = last->GetDeoptId();
+    instr->CopyDeoptIdFrom(*last);
     instr->env()->set_deopt_id(instr->deopt_id_);
 
     map_.Insert(instr);
     emitted_.Add(instr);
   }
 
   FlowGraph* flow_graph_;
   Map map_;
   const ZoneGrowableArray<BlockEntryInstr*>& loop_headers_;
   GrowableArray<BlockEntryInstr*> pre_headers_;
@@ skipping 2169 matching lines @@
     }
   } while (CanonicalizeMaxBoundary(&max) ||
            CanonicalizeMinBoundary(&canonical_length));
 
   // Failed to prove that maximum is bounded with array length.
   return false;
 }
 
 
 }  // namespace dart