Reject deprecated language features.

dart/tests/compiler/dart2js/resolver_test.dart

 // Copyright (c) 2012, 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.
 
 import 'dart:uri';
 
 import "../../../sdk/lib/_internal/compiler/implementation/dart2jslib.dart"
        hide TreeElementMapping, TreeElements, SourceString;
 import "../../../sdk/lib/_internal/compiler/implementation/resolution/resolution.dart";
 import "../../../sdk/lib/_internal/compiler/implementation/elements/elements.dart";
@@ skipping 586 matching lines @@
                           class B extends A {}
                           main() { return new A(); }""");
   FunctionElement mainElement = compiler.mainApp.find(MAIN);
   compiler.resolver.resolve(mainElement);
   Expect.equals(0, compiler.warnings.length);
   Expect.equals(1, compiler.errors.length);
   Expect.equals(MessageKind.CYCLIC_CLASS_HIERARCHY,
                 compiler.errors[0].message.kind);
 
   compiler = new MockCompiler();
-  compiler.parseScript("""interface A extends B {}
-                          interface B extends A {}
+  compiler.parseScript("""abstract class A extends B {}
+                          abstract class B extends A {}
                           class C implements A {}
                           main() { return new C(); }""");
   mainElement = compiler.mainApp.find(MAIN);
   compiler.resolver.resolve(mainElement);
   Expect.equals(0, compiler.warnings.length);
   Expect.equals(1, compiler.errors.length);
   Expect.equals(MessageKind.CYCLIC_CLASS_HIERARCHY,
                 compiler.errors[0].message.kind);
 
   compiler = new MockCompiler();
@@ skipping 188 matching lines @@
         var d = new D();
         --d;
       }""";
   final compiler = compileScript(script);
 
   checkMemberResolved(compiler, 'A', operatorName('+', false));
   checkMemberResolved(compiler, 'B', operatorName('+', false));
   checkMemberResolved(compiler, 'C', operatorName('-', false));
   checkMemberResolved(compiler, 'D', operatorName('-', false));
 }