Crashing on documentation comment types

[piksel]

Hello!
I tried running InferNull on the SharpZipLib source and it failed with a duplicate key exception.
I added some debugging output to see what is going on, and it seems like it chokes on the documentation comment types:

Perhaps this is a known issue? I will try substituting the missing SyntaxTypes to continue testing.

The initial duplicate key exception was thrown in ICSharpCode.NullabilityInference.SyntaxToNodeMapping.CreateNewNode() and the missing key was in ICSharpCode.NullabilityInference.SyntaxToNodeMapping[TypeSyntax syntax]