Add CrossGen2 Dockerfiles for the various options we want to perf test

[MichaelSimons]

This PR is intended to produce the images we would like to perf test as discussed in #1791.

Related to #1820

[MichaelSimons]

@davidwrighton - can you help me out with the correct crossgen2 build args here?

This is for the following scenario:

I see a fourth option which is the runtime uses composite images and aspnet does as well, but they do not use a unified composite image, but rather one built locally to the particular image.

[davidwrighton]

You need a -r argument to reference the runtime level bits. So, add an argument like -r /dotnet/shared/Microsoft.NETCore.App/$DOTNET_VERSION/*.dll to the command line.

[davidwrighton]

btw, does the change to publish crossgen2 binaries work? I wasn't able to test the end to end scenario without checking in.

[MichaelSimons]

Thanks @davidwrighton for the guidance on which args to use. I did run into an issue with the arg which I am not sure if it is a known issue or something wrong with my usage. I had issues when -r was specified just before the input-files. The following Dockerfile snippets illustrate what I mean.

Broken - error regarding no input-files specified

    # Crossgen .NET Core
    && /crossgen2/crossgen2 \
        --composite --inputbubble -O --Os \
        -o /usr/share/dotnet/shared/Microsoft.AspNetCore.App/$ASPNET_VERSION/Microsoft.AspNetCore.App.SharedFramework.dll \
        -r /usr/share/dotnet/shared/Microsoft.NETCore.App/$DOTNET_VERSION/*.dll \
        /usr/share/dotnet/shared/Microsoft.AspNetCore.App/$ASPNET_VERSION/*.dll

Working

    # Crossgen .NET Core
    && /crossgen2/crossgen2 \
        --composite --inputbubble -O --Os \
        -r /usr/share/dotnet/shared/Microsoft.NETCore.App/$DOTNET_VERSION/*.dll \
        -o /usr/share/dotnet/shared/Microsoft.AspNetCore.App/$ASPNET_VERSION/Microsoft.AspNetCore.App.SharedFramework.dll \
        /usr/share/dotnet/shared/Microsoft.AspNetCore.App/$ASPNET_VERSION/*.dll

[MichaelSimons]

btw, does the change to publish crossgen2 binaries work

I hooked-up the docker unit tests which run an e2e app scenario. The tests are passing which is encouraging.

[MichaelSimons]

I am still working on defining the various SDK images.

[MichaelSimons]

This is a temporary solution I built and uploaded until we get on a build that includes the official crossgen2 artifacts - dotnet/runtime#34623

[MichaelSimons]

I'm going to merge. Feel free to provide feedback at any time and we can refactor. This is still evolving.