Reapply "Tweak public APIs and use them in patch_sdk, dart2js, and kernel-service.""

pkg/front_end/lib/src/fasta/builder/library_builder.dart

 // Copyright (c) 2016, 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 fasta.library_builder;
 
 import '../combinator.dart' show Combinator;
 
 import '../errors.dart' show internalError;
 
@@ skipping 29 matching lines @@
 
   final Uri fileUri;
 
   final String relativeFileUri;
 
   LibraryBuilder partOfLibrary;
 
   /// True if a compile-time error has been reported in this library.
   bool hasCompileTimeErrors = false;
 
+  bool mayImplementRestrictedTypes = false;
+
   LibraryBuilder(Uri fileUri, this.scope, this.exports)
       : fileUri = fileUri,
         relativeFileUri = relativizeUri(fileUri),
         scopeBuilder = new ScopeBuilder(scope),
         exportScopeBuilder = new ScopeBuilder(exports),
         super(null, -1, fileUri);
 
   Loader get loader;
 
   Uri get uri;
@@ skipping 116 matching lines @@
   /// Don't use for scope lookup. Only use when an element is known to exist
   /// (and not a setter).
   Builder operator [](String name) {
     return scope.local[name] ?? internalError("Not found: '$name'.");
   }
 
   Builder lookup(String name, int charOffset, Uri fileUri) {
     return scope.lookup(name, charOffset, fileUri);
   }
 }