When DefaultFormalParameter, don't use ParameterKind.REQUIRED.

pkg/analyzer/test/generated/parser_test.dart

Index: pkg/analyzer/test/generated/parser_test.dart
diff --git a/pkg/analyzer/test/generated/parser_test.dart b/pkg/analyzer/test/generated/parser_test.dart
index e4b714c87b4ee8294346fb0f6d242278b999e0d0..a7638b834fe80685b9393c3cd54a39d05ea47e45 100644
--- a/pkg/analyzer/test/generated/parser_test.dart
+++ b/pkg/analyzer/test/generated/parser_test.dart
@@ -2166,6 +2166,8 @@ class Foo {
     expectNotNullIfNoErrors(list);
     listener
         .assertErrorsWithCodes([ParserErrorCode.NAMED_PARAMETER_OUTSIDE_GROUP]);
+    expect(list.parameters[0].kind, ParameterKind.REQUIRED);
+    expect(list.parameters[1].kind, ParameterKind.NAMED);
   }
 
   void test_nonConstructorFactory_field() {
@@ -2292,6 +2294,8 @@ class Foo {
     expectNotNullIfNoErrors(list);
     listener.assertErrorsWithCodes(
         [ParserErrorCode.POSITIONAL_PARAMETER_OUTSIDE_GROUP]);
+    expect(list.parameters[0].kind, ParameterKind.REQUIRED);
+    expect(list.parameters[1].kind, ParameterKind.POSITIONAL);
   }
 
   void test_redirectingConstructorWithBody_named() {