Reapply "Add support for generic function type syntax, part 1"

pkg/analyzer/lib/src/summary/summarize_ast.dart

Index: pkg/analyzer/lib/src/summary/summarize_ast.dart
diff --git a/pkg/analyzer/lib/src/summary/summarize_ast.dart b/pkg/analyzer/lib/src/summary/summarize_ast.dart
index 46b7b2d9990fef15813062a70c771c1601d6693a..7eb3ad549b49e9e2fdc43a530e536be6212e7a77 100644
--- a/pkg/analyzer/lib/src/summary/summarize_ast.dart
+++ b/pkg/analyzer/lib/src/summary/summarize_ast.dart
@@ -567,7 +567,7 @@ class _SummarizeAstVisitor extends RecursiveAstVisitor {
       NodeList<Annotation> annotations,
       bool isFinal,
       bool isConst,
-      TypeName type,
+      TypeAnnotation type,
       bool assignPropagatedTypeSlot,
       SimpleIdentifier declaredIdentifier) {
     UnlinkedVariableBuilder b = new UnlinkedVariableBuilder();
@@ -615,7 +615,7 @@ class _SummarizeAstVisitor extends RecursiveAstVisitor {
       int nameOffset,
       bool isGetter,
       bool isSetter,
-      TypeName returnType,
+      TypeAnnotation returnType,
       FormalParameterList formalParameters,
       FunctionBody body,
       bool isTopLevel,
@@ -764,7 +764,7 @@ class _SummarizeAstVisitor extends RecursiveAstVisitor {
    * parameter and store them in [b].
    */
   void serializeFunctionTypedParameterDetails(UnlinkedParamBuilder b,
-      TypeName returnType, FormalParameterList parameters) {
+      TypeAnnotation returnType, FormalParameterList parameters) {
     EntityRefBuilder serializedReturnType = serializeTypeName(returnType);
     if (serializedReturnType != null) {
       b.type = serializedReturnType;
@@ -933,8 +933,13 @@ class _SummarizeAstVisitor extends RecursiveAstVisitor {
    * a [EntityRef].  Note that this method does the right thing if the
    * name doesn't refer to an entity other than a type (e.g. a class member).
    */
-  EntityRefBuilder serializeTypeName(TypeName node) {
-    return serializeType(node?.name, node?.typeArguments);
+  EntityRefBuilder serializeTypeName(TypeAnnotation node) {
+    if (node is TypeName) {
+      return serializeType(node?.name, node?.typeArguments);
+    } else if (node != null) {
+      throw new ArgumentError('Cannot serialize a ${node.runtimeType}');
+    }
+    return null;
   }
 
   /**
@@ -1397,14 +1402,6 @@ class _SummarizeAstVisitor extends RecursiveAstVisitor {
   }
 
   /**
-   * Helper method to determine if a given [typeName] refers to `dynamic`.
-   */
-  static bool isDynamic(TypeName typeName) {
-    Identifier name = typeName.name;
-    return name is SimpleIdentifier && name.name == 'dynamic';
-  }
-
-  /**
    * Compute the API signature of the unit and record it.
    */
   static void _computeApiSignature(UnlinkedUnitBuilder b) {