Evaluate compile-time constants of metadata.

dart/tests/compiler/dart2js/metadata_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('compiler_helper.dart');
 
 #import('../../../lib/compiler/implementation/elements/elements.dart');
 #import('../../../lib/compiler/implementation/leg.dart');
 
 void testClassMetadata() {
   // TODO(ahe): native should be "const", not "final".
   final source = """final native = 'xyz';
                     @native class Foo {}
                     main() {}""";
 
   check(compiler, element) {
     Expect.isFalse(element.metadata.isEmpty());
+    Expect.isTrue(element.metadata.tail.isEmpty());
     MetadataAnnotation annotation = element.metadata.head;
-    Expect.isNotNull(annotation);
+    annotation.ensureResolved(compiler);
     Constant value = annotation.value;
-    return; // TODO(ahe): I'm working on the following.
-    Expect.isNotNull(value);
+    Expect.stringEquals('xyz', value.value.slowToString());
   }
 
   compileAndCheck(source, 'Foo', check);
 }
 
 void testTopLevelMethodMetadata() {
   // TODO(ahe): native should be "const", not "final".
   final source = """final native = 'xyz';
                     @native
                     main() {}""";
 
   check(compiler, element) {
     Expect.isFalse(element.metadata.isEmpty());
+    Expect.isTrue(element.metadata.tail.isEmpty());
     MetadataAnnotation annotation = element.metadata.head;
-    Expect.isNotNull(annotation);
+    annotation.ensureResolved(compiler);
     Constant value = annotation.value;
-    return; // TODO(ahe): I'm working on the following.
-    Expect.isNotNull(value);
+    Expect.stringEquals('xyz', value.value.slowToString());
   }
 
   compileAndCheck(source, 'main', check);
 }
 
 void main() {
   testClassMetadata();
   testTopLevelMethodMetadata();
 }