Don't treat typedef-typed formal parameters as funtion-type from resynthesize from Kernel.

pkg/analyzer/lib/src/dart/element/element.dart

Index: pkg/analyzer/lib/src/dart/element/element.dart
diff --git a/pkg/analyzer/lib/src/dart/element/element.dart b/pkg/analyzer/lib/src/dart/element/element.dart
index e93f63573437ff5f93617264e8dbe9ae32a2d650..58d955db59dd29d40f3033049aa0abd2bd5fe26f 100644
--- a/pkg/analyzer/lib/src/dart/element/element.dart
+++ b/pkg/analyzer/lib/src/dart/element/element.dart
@@ -8481,7 +8481,7 @@ class ParameterElementImpl extends VariableElementImpl
     if (_kernel != null && _type == null) {
       kernel.DartType type = _kernel.type;
       _type = enclosingUnit._kernelContext.getType(this, type);
-      if (type is kernel.FunctionType) {
+      if (type is kernel.FunctionType && type.typedefReference == null) {
         _parameters = new List<ParameterElement>(
             type.positionalParameters.length + type.namedParameters.length);
         int index = 0;