anchor.diff:      if (name == 'dart.core') isCoreLibrary = true;
     }
   
  -  void endLiteralString(int count) {
  -    assert(count == 0); // TODO(sigmund): handle interpolation
  +  void endLiteralString(int interpolationCount, Token endToken) {
  +    assert(interpolationCount == 0); // TODO(sigmund): handle interpolation
     }
   
     void endMember() {
  
positive.code:             : ReferenceKind.topLevelFunction,
          typeVariables?.length ?? 0 /* todo */);
    }
    void endTypeArguments(int count, Token beginToken, Token endToken) {
      debugEvent("TypeArguments");
      push(popList(count) ?? const []);
  
negative.code:   parser.parseUnit(scan(contents).tokens);
    return listener.topScope.unit;
  }
  
  /// Builder for constant expressions.
  ///
  /// Any invalid subexpression is denoted with [Invalid].
  