code: function SymbolDef(scope, orig, init) {
        this.name = orig.name;
        this.orig = [ orig ];
        this.init = init;
        this.eliminated = 0;
        this.scope = scope;
        this.references = [];
        this.replaced = 0;
        this.global = false;
        this.export = false;
        this.mangled_name = null;
        this.undeclared = false;
        this.id = SymbolDef.next_id++;
    }
docs: *********************************************************************
  
  A JavaScript tokenizer / parser / beautifier / compressor.
  https://github.com/mishoo/UglifyJS2
  
  -------------------------------- (C) ---------------------------------
  
  Author: Mihai Bazon
  <mihai.bazon@gmail.com>
  http://mihai.bazon.net/blog
  
  Distributed under the BSD license:
  
  Copyright 2012 (c) Mihai Bazon <mihai.bazon@gmail.com>
  
  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 with the distribution.
  
  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER “AS IS” AND ANY
  EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE
  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
  OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
  TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
  THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  SUCH DAMAGE.
  
  *********************************************************************