Remove unneeded variable usage analysis.

src/parser.cc

 // Copyright 2006-2008 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 3238 matching lines @@
   //   '(' Expression ')'
 
   Expression* result = NULL;
   switch (peek()) {
     case Token::THIS: {
       Consume(Token::THIS);
       if (is_pre_parsing_) {
         result = VariableProxySentinel::this_proxy();
       } else {
         VariableProxy* recv = top_scope_->receiver();
-        recv->var_uses()->RecordRead(1);
         result = recv;
       }
       break;
     }
 
     case Token::NULL_LITERAL:
       Consume(Token::NULL_LITERAL);
       result = NEW(Literal(Factory::null_value()));
       break;
 
@@ skipping 1819 matching lines @@
       parser.ParseLazy(script_source, name,
                        start_position, end_position, is_expression);
   return result;
 }
 
 
 #undef NEW
 
 
 } }  // namespace v8::internal