anchor.diff:  
     KernelToLocalsMap get localsMap => _currentFrame.localsMap;
   
  +  Map<ir.VariableDeclaration, HInstruction> get letBindings =>
  +      _currentFrame.letBindings;
  +
     JCommonElements get _commonElements => _elementMap.commonElements;
   
     KernelToTypeInferenceMap get _typeInferenceMap =>
  
positive.code:   TypeBuilder typeBuilder;
  
    final NativeEmitter nativeEmitter;
  
    // [ir.Let] and [ir.LocalInitializer] bindings.
    final Map<ir.VariableDeclaration, HInstruction> letBindings =
        <ir.VariableDeclaration, HInstruction>{};
  
    /// True if we are visiting the expression of a throw statement; we assume
    /// this is a slow path.
  
negative.code:     }
  
      bool heuristicSayGoodToGo() {
        // Don't inline recursively,
        if (_inliningStack.any((entry) => entry.function == function)) {
          return false;
        }
  