Rename CoreFx.Private.TestUtilities and reference it in slns

[ViktorHofer]

This fixes the issue where VS refuses to build the test library because it has a reference to TestUtilities which isn't included in the sln. That wasn't a problem before but it seems now that we turned on project restore for everything or because we are using nuget static graph evaluation VS isn't happy about this anymore and errors.

Also I'm renaming CoreFx.Private.TestUtilities to TestUtilities as we don't want to use the corefx term anymore and don't need private in it anymore as well as we don't produce a package for that library anymore.

I didn't rename CoreFx.Private.TestUtilities.Unicode as I don't have any context about that test library but I hope @GrabYourPitchforks will do the same for it.

Fixes #31876

[ghost]

Tagging @ViktorHofer as an area owner

[ViktorHofer]

cc @GrabYourPitchforks

[ViktorHofer]

That's the script that I ran:

foreach ($slnFile in Get-ChildItem -Recurse -Path "*" -Filter *.sln)
{
    $parentDir = (get-item $slnFile.FullName).Directory.FullName
    $testsDir = Join-Path $parentDir tests
    if (Test-Path $testsDir)
    {
        dotnet sln $slnFile.FullName add -s tests Common\tests\TestUtilities\TestUtilities.csproj
    }
}

[safern]

Curious, what is this program for?

[ViktorHofer]

@stephentoub

[akoeplinger]

It's a tool that converts xunit tests into a simple app that doesn't depend on the xunit runner, we use it for bringing up webassembly on netcore mono as a lot of the xunit machinery doesn't work there.

[safern]

I see. Didn't know if this was for pre-consolidation.

[safern]

Would changing the BOM marker change anything?

[ViktorHofer]

Unsure, but I don't care much assuming we won't change these files again anytime soon (now that there is no target framework in them anymore).

[safern]

LGTM. Question, should we also rename: CoreFx.Private.TestUtilities.Unicode, to TestUtilities.Unicode ?

[ViktorHofer]

I didn't rename CoreFx.Private.TestUtilities.Unicode as I don't have any context about that test library but I hope @GrabYourPitchforks will do the same for it.

[GrabYourPitchforks]

Feel free to rename the Unicode project as well per Santi's suggestion. Otherwise if you don't get to it as part of this PR I'll send a separate PR for it.

[ViktorHofer]

Failures are known infra ones.

[ViktorHofer]

@GrabYourPitchforks please send one, I'll be OOF rest of the week.