Add test for source-built bundled NativeAOT.

[tmds]

Contributes to dotnet/source-build#1215.

cc @MichaelSimons @jkotas @omajid

[mthalman]

Ideally, this would be skipped at the test level with SkippableFact. This should be possible because, at a minimum, the SDK root location is known via environment variable. If that approach doesn't work out, it'd be good to at least write something to the output, via DotNetHelper.OutputHelper, that this is being skipped and the reason why.

[tmds]

Ideally, this would be skipped at the test level with SkippableFact.

The project has no reference to a library that provides SkippableFact. What implementation should be used? Should it be a project reference, or do we want to include the sources into the project?

(isNonPortable && !dotNetHelper.IsMonoRuntime)

Currently, this check is made when the test class was instantiated.

To work nicely with SkippableFact we probably want to have a static check and for that ScenarioTestFixture would be refactored into a static class.

[mthalman]

Actually, it looks like there's already an existing pattern for skipping tests in this repo. It uses the Trait attribute. For example, it skips tests based on platform with this:

scenario-tests/src/Microsoft.DotNet.ScenarioTests.Common/Program.cs

Line 235 in f1715bf

filters.ExcludedTraits.Add("SkipIfPlatform", new List<string>() {$"{platform}"});

(example usage of trait)

It'd be good if that pattern could be used here.

[tmds]

ok, I'll follow that pattern. The trait would be something like: "BundledAotCompiler"?

[mthalman]

Yeah, something like that.

[tmds]

I hadn't used XunitFilters before. From looking at it closer, the IncludedTraits requires all tests to have that trait, so I instead of an included trait ("BundledAotCompiler"), I've implemented it using excluded traits (!"Portable", !"Mono").

@mthalman ptal.