Use a dummy TypeckResults instead of Option<TypeckResults> when linting

[Jarcho]

Based on #157928

This brings the typeck results when linting back to what it was before #73743. The first four commits are from the first PR and handle eagerly fetching the typeck results and the workaround needed for rustdoc. The fifth commit adds a dummy ownerless typeck results and uses that as the initial value for the lint pass. The final commit just removes the now useless typeck_results method.

The dummy table is added to the global context more for convenience. It can't be a static since the lifetime argument is invariant. It could be created just for the linting, but that would need to add an extra lifetime parameter to LateContext and a lot of places downstream of that which would be a huge pain.

[rustbot]

clippy is developed in its own repository. If possible, consider making this change to rust-lang/rust-clippy instead.

cc @rust-lang/clippy

[rustbot]

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[folkertdev]

r? types

[Jarcho]

The line the error is complaining about doesn't even exist anywhere. What is the miri test even building?

[rustbot]

This PR was rebased onto a different main 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.

[rust-bors]

☔ The latest upstream changes (presumably #158924) made this pull request unmergeable. Please resolve the merge conflicts by rebasing.