move tests from tests/rustdoc-ui/ to tests/rustdoc-ui/lints/ where applicable

[lolbinarycat]

a few i've spotted just at a glance:

• unescaped_backticks.rs
• unportable-markdown.rs

additionally, any tests related to intra-doc links should be moved to the intra-doc directory.

[yegeunyang]

@rustbot claim

[lolbinarycat]

@yegeunyang could you hold off on this until #136400 is merged? otherwise whichever PR isn't merged first will have a bunch of annoying merge conflicts.

[yegeunyang]

@yegeunyang could you hold off on this until #136400 is merged? otherwise whichever PR isn't merged first will have a bunch of annoying merge conflicts.

Of course!

[yegeunyang]

@rustbot release-assignment

[lolbinarycat]

additionally, there's several tests involving deref that could get moved to tests/rustdoc/deref.

[jusexton]

Skimmed the rustdoc-ui tests and put together hopefully a more concrete list of files that fall under the scope of this issue. I wouldn't mind making the changes once #136400 is merged.

Lints
custom_code_classes_in_docs-warning3.rs
diagnostic-width.rs
include-str-bare-urls.rs
remap-path-prefix-lint.rs
unescaped_backticks.rs
unportable-markdown.rs
redundant-explicit-links-123677.rs

Intra doc
circular-intra-doc-link-48414.rs
disambiguator-endswith-named-suffix.rs

Deref
deref-generic.rs
ice-blanket-impl-56701.rs
recursive-deref-ice.rs