dart-lang#1400. Add the trivial case and a pattern check (dart-lang#2451)

Add the trivial case and a pattern check

Author: sgrekhov

LanguageFeatures/Extension-types/static_analysis_member_invocation_A06_t02.dart

@@ -32,5 +32,11 @@ main() {
   et1.ceil();
 //    ^^^^
 // [analyzer] unspecified
+// [cfe] unspecified
+
+  var ET1(m2: v1) = et1;
+  var ET1(isOdd: v2) = et1;
+//        ^^^^^
+// [analyzer] unspecified
 // [cfe] unspecified
 }

LanguageFeatures/Extension-types/static_analysis_member_invocation_A06_t07.dart

@@ -0,0 +1,45 @@
+// 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 We say that an extension type declaration DV has an extension
+/// type member named n in the cases where:
+/// - DV declares a member named n.
+/// - DV has no such declaration, but DV has a direct extension type
+///   superinterface V that has an extension type member named n due to a member
+///   declaration DM2, and DV does not declare a member that precludes DM2.
+///
+/// @description Checks that if an extension type `ET` has no superinterface
+/// with a member `m` and doesn't declare it then it is a compile-time error to
+/// call this member
+/// @author [email protected]
+
+// SharedOptions=--enable-experiment=inline-class
+
+extension type ET(int _) {}
+
+main() {
+  ET et = ET(42);
+  et.ceil();
+//   ^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+
+  et.isOdd;
+//   ^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+
+  var ET(isEven: b) = et;
+//       ^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+
+  var n = switch (et) {
+    ET(isEven: true) => true,
+//     ^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+    _ => false
+  };
+}