Add .NET 10 support

[am11]

This strongly-typed enums based implementation is not scaling very well; but for now, lets add 10.0 and soon after lets see if we can make it less verbose to ease up future updates a bit: dotnet/runtime#106599 (comment)

cc @adamsitnik, @lewing

[caaavik-msft]

I've tested this PR against a local build from dotnet/runtime#106599 and it fails because it seems that the .NET 10 SDK doesn't actually allow to target .NET 10, rather it only allows targetting .NET 9. To get things to work we do need to make changes to the SDK validator to allow backwards compatibility. However, this change will still be useful to have in once we do have .NET 10 targeting supported

[am11]

Yup, it's a chicken-egg situation atm, and we will soon be on alpha1 in runtime repo (based on how it was done last year, around this time). I think we can pass --corerun option in local builds that points to built corerun under artifacts/bin or artifacts/tests/coreclr/<platform>/Tests/Core_Root to get the ball rolling?

[timcassell]

GitHub won't let me add a comment on the actual line... I think the TryParse method needs to be updated to account for the underscore.

internal static bool TryParse(string runtime, out RuntimeMoniker runtimeMoniker)
{
    int index = runtime.IndexOf('-');
    if (index >= 0)
    {
        runtime = runtime.Substring(0, index);
    }

    // Monikers older than Net 10 don't use any version delimiter, newer monikers use _ delimiter.
    if (Enum.TryParse(runtime.Replace(".", string.Empty), ignoreCase: true, out runtimeMoniker))
    {
        return true;
    }
    return Enum.TryParse(runtime.Replace('.', '_'), ignoreCase: true, out runtimeMoniker);
}

I don't have a 10.0 sdk version, so I didn't test.

[timcassell]

Suggested change

	[InlineData("net70")]
	[InlineData("net80")]
	[InlineData("net90")]
	[InlineData("net10_0")]
	[InlineData("net7.0")]
	[InlineData("net8.0")]
	[InlineData("net9.0")]
	[InlineData("net10.0")]

[am11]

IMHO the best direction would be to introduce something similar to the [SupportedOSPlatform], such as [SupportedFramework("netX.0")], which would provide indefinite scalability. The current hardcoded enum approach doesn't scale well, which was precisely why [SupportedPlatform("")] (introduced in .NET 5.0) was designed to be string-based instead of enum-based—managing an enum over the years would have been a maintenance nightmare.

This transition to .NET 10.0 might be an ideal time to consider such a change and start deprecating the old enum, with the goal of fully removing it after a few release cycles. Additionally, pseudo-TFMs like nativeaot9.0 feel somewhat unnatural compared to the broader ecosystem’s conventions, such as using net9.0 combined with --aot (e.g., dotnet new console -f net9.0 --aot) or simply setting PublishAot=true.

[timcassell]

I don't understand how [SupportedFramework("netX.0")] would be used. I think you should open an issue with more details rather than discuss it here. And/or create a WIP PR showcasing a new system.