I couldn't figure out the best area label to add to this PR. If you have write-permissions please help me learn by adding exactly one area label.

@JunTaoLuo @maryamariyan @ericstj kindly asking for a review. This deletes all the aspnetcore infra that we ported over as well as it isn't used and replaced the few callers that used some of the features with runtime helpers.

@maryamariyan and @JunTaoLuo will need to review this one. I thought we had eliminated all dead code, so removing this might be removing something they need.

I thought we had eliminated all dead code, so removing this might be removing something they need.

@ericstj this work item is tracked in issue #37821 (comment), second item under code cleanup.

That was all dead code, so no worries.

Yea we were sort of expecting some of the Testing Infra to be unused. Some of the functionality have analogous counterparts in dotnet/runtime and some of the infra was created to support AspNetCore builds. I took a brief look and the removed code looks reasonable.