roslyn: Issue with SyntaxWalker and Malformed XML comments

Version Used: 2.8 Libraries, C# and VB.Net, Visual Studio 15.7.1 Steps to Reproduce:

    ''' <summary> ' XML Element without End Tag
    '''   Some XML text that is part of summary
    '''' This is a comment and not part of XML Summary
    ''' </summary> ' This is XML Text and not a close Summary

    /// <summary> /* XML Element without End Tag */
    ///   Some XML text that is part of summary
    //// This is a comment and not part of XML Summary
    /// </summary> /*  This is XML Text and not a close Summary */

1. In C#, VB and Visual Studio the above XML document comment is allowed but the SyntaxWalker returns unexpected results and you can’t create the above with SyntaxFactory.XmlElement(StartTag, Content, EndTag) if the end tag is empty.
2. The Visitor for the XmlElement node contains the Summary element, Content element with an empty EndTag

Expected Behavior: The compilers and Visual Studio should complain about Malformed Document comments or the SyntaxWalker should treat the embedded comments as part of the content Actual Behavior: No errors in Compilers or Visual Studio but SyntaxWalker passes in malformed XML