Aspnetcore: Component compilation support needs to add diagnostics for markup errors

[rynowak]

The Blazor compiler adds diagnostics for things like missing end tags, and mismatched start/end tags. We don't have that support yet for the new component compiler.

This should probably done in the IR lowering phase.

Please find a few skipped tests in the aspnet/AspNetCore-Tooling repo that refer to this issue.

[DNF-SaS]

@rynowak General Question about the repo-merge of Blazor into the AspNetCore-Repo: how can one distinct issues related to blazor from all the other ones? (in this case, this one was only found because I knew that you're closely related to Blazor - looking at labels/projects/whatever, I don't see any blazor-specific classifier)
Sorry for being off-topic and thanks for your answer!

[rynowak]

Thanks for asking, I think we'll probably end up using a label like area-Components or area-Blazor. Right now it's still the holidays here so the dust hasn't quite settled yet 😆

[rynowak]

You can also look at https://github.com/orgs/aspnet/projects/19 where we're tracking the components productization work