Performance tests do not run under netfx targetgroup

[maryamariyan]

Seems like we don't support running perf tests in netfx.

For example when running:

msbuild src\System.IO.Compression\tests\Performance\ /t:rebuildandtest /p:ConfigurationGroup=Release /p:TargetOs=Windows_NT /p:Performance=true /p:targetgroup=netfx

it just ends up running with default targetgroup (being netcoreapp)

Although there are other ways (e.g. using BenchmarkDotnet) to do performance testing in netfx, it could still be useful to enable this in cases when we want to compare netfx vs netcoreapp performances with each other for the existing perf tests written in corefx.

Note: When trying to test the above script I believe you need to add netfx value in the configuration.props file here.

cc: @danmosemsft @safern

[ViktorHofer]

Duplicate of https://github.com/dotnet/corefx/issues/19200