anchor.diff:  
           #if ONEPASS
           ScopeChain = ref [globalScope]
  -        ContainedScopes = containedScopes
  -        MissingClosures = new Dict<string, List<Scope ref>>()
           #endif
  -
         } |> statementList |> Tree.Block
   
       Tree.FunctionFast(None, globalScope, globalAst)
  
positive.code: 
      #if ONEPASS
      ScopeChain = ref []
      MissingClosures = null
      ContainedScopes = null
      #endif
    }
    
  
negative.code:   let parse (source:string) (env:Env) =
      let lexer = source |> Lexer.create
      let globalScope = ref {Ast.Scope.NewGlobal with GlobalLevel = 0}
      let globalAst = 
        {parserDefinition with 
          Env = env
  