Simply use the variable index to put them into the right ScopeInfo slot rather than sorting

src/ast/variables.cc

 // Copyright 2011 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/ast/variables.h"
 
 #include "src/ast/scopes.h"
 #include "src/globals.h"
 
 namespace v8 {
@@ skipping 47 matching lines @@
 
 
 bool Variable::IsStaticGlobalObjectProperty() const {
   // Temporaries are never global, they must always be allocated in the
   // activation frame.
   return (IsDeclaredVariableMode(mode_) && !IsLexicalVariableMode(mode_)) &&
          scope_ != NULL && scope_->is_script_scope();
 }
 
 
-int Variable::CompareIndex(Variable* const* v, Variable* const* w) {
-  int x = (*v)->index();
-  int y = (*w)->index();
-  // Consider sorting them according to type as well?
-  return x - y;
-}
-
 }  // namespace internal
 }  // namespace v8