Store pointer instead of reference to LocalVariable in ast and flow graph.

runtime/vm/scopes.h

 // 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.
 
 #ifndef VM_SCOPES_H_
 #define VM_SCOPES_H_
 
 #include "vm/allocation.h"
 #include "vm/assembler.h"
 #include "vm/growable_array.h"
@@ skipping 52 matching lines @@
   void set_index(int index) {
     ASSERT(!HasIndex());
     ASSERT(index != kUnitializedIndex);
     index_ = index;
   }
 
   void set_invisible(bool value) {
     is_invisible_ = value;
   }
 
-  bool Equals(const LocalVariable& other) const;
+  bool Equals(const LocalVariable* other) const;
 
   // Map the frame index to a bit-vector index.  Assumes the variable is
   // allocated to the frame.
   // var_count is the total number of stack-allocated variables including
   // all parameters.
   int BitIndexIn(intptr_t var_count) const;
 
   // Name of the internal variable that is used to save the context chain
   // on function entry.
   static const char* kSavedContextVarName;
@@ skipping 260 matching lines @@
   intptr_t end_token_pos_;    // Token index of end of scope.
   GrowableArray<LocalVariable*> variables_;
   GrowableArray<SourceLabel*> labels_;
 
   DISALLOW_COPY_AND_ASSIGN(LocalScope);
 };
 
 }  // namespace dart
 
 #endif  // VM_SCOPES_H_