Allow bare CR in ////-style comment.

[qnighy]

Fixes#40624 in a way that bare CR is allowed in all non-doc comments.

[rust-highfive]

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[estebank]

@bors r+ rollup

[bors]

📌 Commit 0e8e45c has been approved by estebank

[nikomatsakis]

@qnighy thanks for the bug fix! But I have a question. I think the more fundamental problem here is that the test for "is this a doc comment" is kind of "open-coded" here. That boolean that you modified might be better called "starts-with-triple-slash" or "is-maybe-doc-comment". If you look a bit later on in the file, you'll see some logic that invokes is_doc_comment() to test whether the comment is really a doc-comment. Do you think you could modify the \r test to use that helper so that things are more DRY?

[qnighy]

@nikomatsakis I've left it undone because scan_block_comment() does the similar thing and I thought it might be on purpose. If not, I will sort it out when I have time.

[nikomatsakis]

@qnighy not that I know of...