Delete more type equivalence logic (#85507)

Delete more type equivalence logic (#85507)

* Delete more type equivalence logic

In .NET Native times we could have a situation where two different `MethodTable` pointers represented the same type. This could happen for cloned types, or structurally equivalent parameterized types. The cloned type concept was never used in Native AOT. The structural equivalence disappeared in https://github.com/dotnet/runtimelab/commit/0ef7bd6cfe129f4c308f5d6dae1eccf48c3cdff4. Neither of those seems useful. So getting rid of some of the vestiges.

* Delete more stuff

* Remember statically present pointer and mdarrays