Documentation for System.Reflection.Metadata (package version 1.5.0) has gone missing

There appears to be a XML doc problem with System.Reflection.Metadata, version 1.5.0. Despite being quite thoroughly documented [in the original source code](https://github.com/dotnet/corefx/tree/master/src/System.Reflection.Metadata/src/System/Reflection), most or all of that documentation appears to get lost on its way to VS IntelliSense and the online [.NET API Browser](https://docs.microsoft.com/en-us/dotnet/api/system.reflection.metadata).

I checked some of the XML documentation files in the NuGet package that sits in my local NuGet package cache at `C:\Users\stakx\.nuget\packages\system.reflection.metadata\1.5.0\lib\netstandard2.0\System.Reflection.Metadata.xml`—it contains the markup skeleton but no actual documentation text.