* Normalizing the Interop.Extensions types to implement the same base members
* Adding some base managed types for various handles
* Regenerating bindings for LLVM 11.0.0
* Update to LLVM 10.0.0
* Updating dependencies to their latest stable versions
* Upgrading to .NET Core 3.1
* Update to LLVM 10.0.0
* Fixing up the Interop.Extensions
* Updating the Linux rid to ubuntu.18.04-x64
* Fixing the build scripts to properly opt out of the first time experience.
* Marking Microsoft.Net.Compilers.Toolset with PrivateAssets="all"
* Updating Microsoft.NET.Test.Sdk to 16.1.1
* Updating nunit to 3.12.0
* Upgrading netcoreapp projects to 2.1, since 2.0 is end of life
* Adding a nuspec file for creating the libLLVM package.