Code changes to allow 'using static unsafe'

[CyrusNajmabadi]

Fixes #67329

Relates to test plan #56323

[CyrusNajmabadi]

bad github diffs. tests were added, pushing prior tests down. github registering as a change.

[CyrusNajmabadi]

this test moved down so it could remain with the rest of the variants added for it. I couldn't add teh variants next to it, or github blewup thinking all the tests had changed.

[CyrusNajmabadi]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 2 pipeline(s).

[jcouv]

Same comment here. I would not make CheckUnsafeModifier conditional on langver check. Comment above will need to be updated accordingly #Closed

[CyrusNajmabadi]

done.

[jcouv]

Was a test affected?

[CyrusNajmabadi]

yes. many tests were affected by this.

[jcouv]

Done with review pass (iteration 16)

[CyrusNajmabadi]

@jcouv ptal :)

[jcouv]

Done with review pass (iteration 20)

[jcouv]

LGTM Thanks (iteration 20)

[cston]

UsingStatic_UnsafeType_CSharp11_NoUnsafeFlag

It looks like the added tests each have 4 variants, { C# 11, C# next } x { no -unsafe, -unsafe }, and each test tests binding and parsing separately. But the results of the parser should be the same across all variants (and the parser does not depend on CSharpCompilationOptions which contains the unsafe setting).

Given that, would it make sense to combine the variants? For instance:

[Theory]
[InlineData(LanguageVersion.CSharp10)]
[InlineData(LanguageVersion.CSharp11)]
public void UsingStatic_UnsafeType(LanguageVersion languageVersion)
{
    var parseOptions = TestOptions.Regular.WithLanguageVersion(languageVersion);
    var text = "...";

    if (languageVersion == LanguageVersion.CSharp10)
    {
        CreateCompilation(text, parseOptions: parseOptions).VerifyDiagnostics(...);
        CreateCompilation(text, parseOptions: parseOptions, options: TestOptions.UnsafeDebugDll).
            VerifyDiagnostics(...);
    }
    else
    {
        CreateCompilation(text, parseOptions: parseOptions).VerifyDiagnostics(...);
        CreateCompilation(text, parseOptions: parseOptions, options: TestOptions.UnsafeDebugDll).
            VerifyDiagnostics(...);
    }

    UsingTree(text, options: parseOptions);
    N(SyntaxKind.CompilationUnit);
    {
        ...
    }
}

[CyrusNajmabadi]

I find theories, which then have different behavior on units, nigh unreadable. I spend more time just trying to understand what the final test is actually testing.

It's also a huge pita when one variant of the test fails, and you continually have to revise and run all the other variants.

I'm a big fan of a test having an input and validating it. A true unit test.