anchor.diff:      this._uc, {
       this.requireValidConst: true,
       this.localFunctions,
  -    Map<String, ParameterElement> parametersInScope,
  +    _VariablesInScope variablesInScope,
       this.becomeSetOrMap: true,
  -  })  : this.parametersInScope =
  -            parametersInScope ?? _parametersInScope(context),
  +  })  : this.variablesInScope = variablesInScope ?? _parametersInScope(context),
           this.isSpreadOrControlFlowEnabled = _isSpreadOrControlFlowEnabled(
               (resynthesizer.library.context.analysisOptions
                       as AnalysisOptionsImpl)
  
positive.code:     return result;
    }
  }
  
negative.code: 
    final List<UnlinkedExecutable> localFunctions;
  
    final _VariablesInScope variablesInScope;
  
    ExprBuilder(
      this.resynthesizer,
  