Add label to E0254

[tvladyslav]

This issue #35513 is a part of #35233.
Looks like it does not break unit tests.
r? @jonathandturner

[rust-highfive]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @jonathandturner (or someone else) soon.

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[sophiajt]

Thanks for the PR!

A couple of things to help you out. There's a quirk in the unit tester that requires you to add one NOTE before it starts testing the labels. I talk about it in the blog post in the section titled Extra Credit.

Once you add the NOTE, you can do a quick test on the suite by running git grep E0254 and looking for other tests that may need updating.

One code style nit. You may want to un-indent the closing curly brace so that it's clear where the block begins and ends:

 (true, _) | (_, true) if binding.is_import() || old_binding.is_import() => {
let mut e = struct_span_err!(self.session, span, E0254, "{}", msg);
e.span_label(span, &"already imported");
e
},

vs

 (true, _) | (_, true) if binding.is_import() || old_binding.is_import() => {
let mut e = struct_span_err!(self.session, span, E0254, "{}", msg);
e.span_label(span, &"already imported");
e
},

[tvladyslav]

Got it! Fixing...

[tvladyslav]

I put new PR #35596 , because I can't make GitHub understand --amend'ed commit.

[dashed]

@crypto-universe you probably needed to force push the commits

[bors]

☔ The latest upstream changes (presumably #35666) made this pull request unmergeable. Please resolve the merge conflicts.

[tvladyslav]

Error message for E0254 is already updated (from another branch).