[rel/18.0] Source code updates from dotnet/dotnet#15288

nohwnd merged 3 commits intorel/18.0microsoft/vstest:rel/18.0from

darc-rel/18.0-8d5be576-a44c-479b-aefd-c4e8b3b67048microsoft/vstest:darc-rel/18.0-8d5be576-a44c-479b-aefd-c4e8b3b67048Copy head branch name to clipboard