AsmDiff: Do not show APIs with protected internal visibility

[carlossanlop]

As seen here: dotnet/core#9220 (comment)

[Zastai]

Curious: why would protected internal not be considered public API just like plain protected would? It adds access from inside the assembly.

In the linked issue, was the intent to remove the constructor in question from the public API?
Then should it not be private protected instead? Plus, if the API diff is taking something from public or protected to internal or private protected, then that is an API break and should absolutely be in the diff.

What I would say is that for the purpose of an API diff protected and protected internal should probably be considered equivalent, and just rendered as protected. Adding/removing internal access to a protected member has no API impact.