Report hint on unmatched show and hide combinators.

pkg/compiler/lib/src/common.dart

 // Copyright (c) 2013, 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.
 
 library dart2js.common;
 
 
 export 'common/tasks.dart' show
     CompilerTask;
 
@@ skipping 14 matching lines @@
     Types;
 
 export 'diagnostics/invariant.dart' show
     invariant;
 
 export 'diagnostics/spannable.dart' show
     SpannableAssertionFailure;
 
 export 'elements/elements.dart' show
     ClassElement,
-    ClosureFieldElement,
     CompilationUnitElement,
     Element,
     Elements,
     FunctionElement,
     FunctionSignature,
     LibraryElement,
     MetadataAnnotation,
     MixinApplicationElement,
     TypedefElement,
     VariableElement;
 
-export 'resolution/resolution.dart' show
-    TreeElements;
-
 export 'tree/tree.dart' show
     Node;
 
 export 'types/types.dart' show
     TypeMask;
 
 export 'universe/universe.dart' show
     CallStructure,
     Selector,
     SelectorKind;
 
 export 'util/util.dart' show
     Link;