Remove unneeded variable usage analysis.

src/ast.h

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 987 matching lines @@
     return !is_this() && name().is_identical_to(n);
   }
 
   bool IsArguments() {
     Variable* variable = AsVariable();
     return (variable == NULL) ? false : variable->is_arguments();
   }
 
   Handle<String> name() const  { return name_; }
   Variable* var() const  { return var_; }
-  UseCount* var_uses()  { return &var_uses_; }
-  UseCount* obj_uses()  { return &obj_uses_; }
   bool is_this() const  { return is_this_; }
   bool inside_with() const  { return inside_with_; }
 
   // Bind this proxy to the variable var.
   void BindTo(Variable* var);
 
  protected:
   Handle<String> name_;
   Variable* var_;  // resolved variable, or NULL
   bool is_this_;
   bool inside_with_;
 
-  // VariableProxy usage info.
-  UseCount var_uses_;  // uses of the variable value
-  UseCount obj_uses_;  // uses of the object the variable points to
-
   VariableProxy(Handle<String> name, bool is_this, bool inside_with);
   explicit VariableProxy(bool is_this);
 
   friend class Scope;
 };
 
 
 class VariableProxySentinel: public VariableProxy {
  public:
   virtual bool IsValidLeftHandSide() { return !is_this(); }
@@ skipping 872 matching lines @@
 #undef DEF_VISIT
 
  private:
   bool stack_overflow_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_AST_H_