Expand lint tables && make clippy happy 🎉
This PR expands the lint tables on `./Cargo.toml` and thereby makes `cargo clippy` exit successfully! 🎉Fixes#15918
## How?
In the beginning there are some warnings for rustc.
Next, and most importantly, there is the clippy lint table. There are a few sections in there.
First there are the lint groups.
Second there are all lints which are permanently allowed with the reasoning why they are allowed.
Third there is a huge list of temporarily allowed lints. They should be removed in the mid-term, but incur a substantial amount of work, therefore they are allowed for now and can be worked on bit by bit.
Fourth there are all lints which should warn.
Additionally there are a few allow statements in the code for lints which should be permanently allowed in this specific place, but not in the whole code base.
## Follow up work
- [ ] Run clippy in CI
- [ ] Remove tidy test (at least `@Veykril` wrote this in #15017)
- [ ] Work on temporarily allowed lints
internal: Record FnAbi
This unfortunately breaks our lub coercions, so will need to look into fixing that first, though I am not sure what is going wrong where...
Stubbed some stuff out for the time being.
`cargo clippy --fix`
This PR is the result of running `cargo clippy --fix && cargo fmt` in the root of the repository. I did not manually review all the changes, but just skimmed through a few of them. The tests still pass, so it seems fine.
Add a new config to allow renaming of non-local defs
With #15656 we started disallowing renaming of non-local items. Although this makes sense there are some false positives that impacted users' workflows. So this config aims to mitigate this by giving users the liberty to disable this feature.
The reason why this is a draft is that I saw one of the tests fail and I am not sure if the "got" result even syntactically makes sense
Test case is :
```rust
check(
"Baz",
r#"
//- /lib.rs crate:lib new_source_root:library
pub struct S;
//- /main.rs crate:main deps:lib new_source_root:local
use lib::S$0;
"#,
"use lib::Baz;"
);
```
```
Left:
use lib::Baz;
Right:
use lib::Baz;Baz
Diff:
use lib::Baz;Baz
```
