Support optional package name arguments to --show-package-warnings

pkg/compiler/lib/src/library_loader.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.
 
 library dart2js.library_loader;
 
 import 'dart:async';
 
 import 'common.dart';
 import 'common/names.dart' show
@@ skipping 1060 matching lines @@
       LibraryDependency tag,
       LibraryElement library) {
     if (tag == null || tag.combinators == null) return;
     for (Combinator combinator in tag.combinators) {
       for (Identifier identifier in combinator.identifiers) {
         String name = identifier.source;
         Element element = library.findExported(name);
         if (element == null) {
           if (combinator.isHide) {
             if (library.isPackageLibrary &&
-                !reporter.options.showPackageWarnings) {
+                reporter.options.hidePackageWarnings) {
               // Only report hide hint on packages if we show warnings on these:
               // The hide may be non-empty in some versions of the package, in
               // which case you shouldn't remove the combinator.
               continue;
             }
             reporter.reportHintMessage(
                 identifier,
                 MessageKind.EMPTY_HIDE,
                 {'uri': library.canonicalUri,
                  'name': name});
@@ skipping 263 matching lines @@
         }
         suffixes.add(const Link<Uri>().prepend(canonicalUri));
       }
       suffixChainMap[library] = suffixes;
       return;
     }
 
     computeSuffixes(rootLibrary, const Link<Uri>());
   }
 }