Fix a type annotation in the parser to make it accept non-literal strings as part URIs in checked m…

tests/language/library_juxtaposition_part.dart

Index: tests/language/library_juxtaposition_part.dart
diff --git a/tests/language/first_class_types_lib1.dart b/tests/language/library_juxtaposition_part.dart
similarity index 89%
copy from tests/language/first_class_types_lib1.dart
copy to tests/language/library_juxtaposition_part.dart
index baadc66015a5ced9bfbdc10f1180715ee714a547..2b1494210f26acc3c43d326922f3fcea44c1217f 100644
--- a/tests/language/first_class_types_lib1.dart
+++ b/tests/language/library_juxtaposition_part.dart
@@ -2,6 +2,4 @@
 // 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.
 
-library lib1;
-
-class A {}
+const c = 47;