Create a new element for generic function types

pkg/analyzer/lib/dart/element/visitor.dart

Index: pkg/analyzer/lib/dart/element/visitor.dart
diff --git a/pkg/analyzer/lib/dart/element/visitor.dart b/pkg/analyzer/lib/dart/element/visitor.dart
index c34c7719ae59161ae247d1f9c06a17e87e036737..dac2d23a7eee25191c1d1d77dae2a8abddac7d32 100644
--- a/pkg/analyzer/lib/dart/element/visitor.dart
+++ b/pkg/analyzer/lib/dart/element/visitor.dart
@@ -122,6 +122,10 @@ class GeneralizingElementVisitor<R> implements ElementVisitor<R> {
       visitElement(element);
 
   @override
+  R visitGenericFunctionTypeElement(GenericFunctionTypeElement element) =>
+      visitElement(element);
+
+  @override
   R visitImportElement(ImportElement element) => visitElement(element);
 
   @override
@@ -241,6 +245,12 @@ class RecursiveElementVisitor<R> implements ElementVisitor<R> {
   }
 
   @override
+  R visitGenericFunctionTypeElement(GenericFunctionTypeElement element) {
+    element.visitChildren(this);
+    return null;
+  }
+
+  @override
   R visitImportElement(ImportElement element) {
     element.visitChildren(this);
     return null;
@@ -342,6 +352,9 @@ class SimpleElementVisitor<R> implements ElementVisitor<R> {
   R visitFunctionTypeAliasElement(FunctionTypeAliasElement element) => null;
 
   @override
+  R visitGenericFunctionTypeElement(GenericFunctionTypeElement element) => null;
+
+  @override
   R visitImportElement(ImportElement element) => null;
 
   @override
@@ -413,6 +426,10 @@ class ThrowingElementVisitor<R> implements ElementVisitor<R> {
       _throw(element);
 
   @override
+  R visitGenericFunctionTypeElement(GenericFunctionTypeElement element) =>
+      _throw(element);
+
+  @override
   R visitImportElement(ImportElement element) => _throw(element);
 
   @override