#2339. Add test for extension named type and a record type (#2366)

Add test for extension named `type` and a record type

LanguageFeatures/Extension-methods/syntax_t07.dart

@@ -0,0 +1,25 @@
+// Copyright (c) 2023, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+/// @assertion an extension declaration is a top-level declaration with a grammar
+/// similar to:
+/// <extension> ::=
+///   `extension' <identifier>? <typeParameters>? `on' <type> `?'? `{'
+///     memberDeclaration*
+///   `}'
+/// Such a declaration introduces its name (the identifier) into the surrounding
+/// scope
+///
+/// @description Check that it is a compile-time error if an extension has the
+/// name `type`. Test record type
+/// @author [email protected]
+
+extension type on (int i,) {}
+//                      ^
+// [analyzer] unspecified
+// [cfe] unspecified
+
+main() {
+  print((int,));
+}