Remove unneeded variable usage analysis.

src/ast.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 49 matching lines @@
 
 VariableProxy::VariableProxy(Handle<String> name,
                              bool is_this,
                              bool inside_with)
   : name_(name),
     var_(NULL),
     is_this_(is_this),
     inside_with_(inside_with) {
   // names must be canonicalized for fast equality checks
   ASSERT(name->IsSymbol());
-  // at least one access, otherwise no need for a VariableProxy
-  var_uses_.RecordRead(1);
 }
 
 
 VariableProxy::VariableProxy(bool is_this)
   : is_this_(is_this) {
 }
 
 
 void VariableProxy::BindTo(Variable* var) {
   ASSERT(var_ == NULL);  // must be bound only once
   ASSERT(var != NULL);  // must bind
   ASSERT((is_this() && var->is_this()) || name_.is_identical_to(var->name()));
   // Ideally CONST-ness should match. However, this is very hard to achieve
   // because we don't know the exact semantics of conflicting (const and
   // non-const) multiple variable declarations, const vars introduced via
   // eval() etc.  Const-ness and variable declarations are a complete mess
   // in JS. Sigh...
   var_ = var;
-  var->var_uses()->RecordUses(&var_uses_);
-  var->obj_uses()->RecordUses(&obj_uses_);
+  var->set_is_used(true);
 }
 
 
 Token::Value Assignment::binary_op() const {
   switch (op_) {
     case Token::ASSIGN_BIT_OR: return Token::BIT_OR;
     case Token::ASSIGN_BIT_XOR: return Token::BIT_XOR;
     case Token::ASSIGN_BIT_AND: return Token::BIT_AND;
     case Token::ASSIGN_SHL: return Token::SHL;
     case Token::ASSIGN_SAR: return Token::SAR;
@@ skipping 380 matching lines @@
     if (kInfinity - max_match_ < node_max_match) {
       max_match_ = kInfinity;
     } else {
       max_match_ += node->max_match();
     }
   }
 }
 
 
 } }  // namespace v8::internal