Update `naked` to use the attribute template

[ehuss]

New rules:

• ❗ attributes.codegen.naked.syntax
• ❗ attributes.codegen.naked.allowed-positions
• ❗ attributes.codegen.naked.duplicates
• ❗ attributes.codegen.naked.target_feature
• ❗ attributes.codegen.naked.abi

Renamed rules:

• attributes.codegen.naked.unsafe-attribute is now attributes.codegen.naked.unsafe

[tshepang]

just 1 comment, otherwise this is good

[rustbot]

:umbrella: The latest upstream changes (possibly 9c6bcbdc3a37c67892f529a6cab35cef4db2926f) made this pull request unmergeable. Please resolve the merge conflicts.

[rustbot]

This PR was rebased onto a different master commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.