Add mutable double boxes for fields.

runtime/vm/il_printer.cc

 // Copyright (c) 2012, 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/il_printer.h"
 
 #include "vm/intermediate_language.h"
 #include "vm/os.h"
 #include "vm/parser.h"
 
@@ skipping 61 matching lines @@
 
 
 void FlowGraphPrinter::PrintOneInstruction(Instruction* instr,
                                            bool print_locations) {
   char str[4000];
   BufferFormatter f(str, sizeof(str));
   instr->PrintTo(&f);
   if (FLAG_print_environments && (instr->env() != NULL)) {
     instr->env()->PrintTo(&f);
   }
-  if (print_locations && (instr->locs() != NULL)) {
+  if (print_locations && (instr->locs_ != NULL)) {
     instr->locs()->PrintTo(&f);
   }
   if (instr->lifetime_position() != -1) {
     OS::Print("%3" Pd ": ", instr->lifetime_position());
   }
   if (!instr->IsBlockEntry()) OS::Print("    ");
   OS::Print("%s", str);
 }
 
 
@@ skipping 898 matching lines @@
       f->Print(" [");
       locations_[i].PrintTo(f);
       f->Print("]");
     }
   }
   f->Print(" }");
   if (outer_ != NULL) outer_->PrintTo(f);
 }
 
 }  // namespace dart