anchor.diff:      libraryNameOffset = node.name.offset;
       libraryNameLength = node.name.length;
       isCoreLibrary = libraryName == 'dart.core';
  +    isCoreLibraryDefiningUnit = isCoreLibrary;
       libraryDocumentationComment =
           serializeDocumentation(node.documentationComment);
       libraryAnnotations = serializeAnnotations(node.metadata);
  
positive.code:     b.variables = variables;
  
      b.publicNamespace = computePublicNamespace(compilationUnit);
      if (isCoreLibrary) {
        b.publicNamespace.names.add(
          UnlinkedPublicNameBuilder(
            name: 'Never',
  
negative.code: 
    /// True if the 'dart:core' library is been summarized.
    bool isCoreLibrary = false;
  
    /// True if the 'dart:core' library defining unit is been summarized.
    bool isCoreLibraryDefiningUnit = false;
  
    /// True is a [PartOfDirective] was found, so the unit is a part.
    bool isPartOf = false;
  