fix bug for large_enum_variants
Fix the discussion problem in the issue of https://github.com/rust-lang/rust-clippy/issues/7666#issuecomment-919654291
About the false positive problem of case:
```rust
enum LargeEnum6 {
A,
B([u8;255]),
C([u8;200]),
}
```
changelog: Fix largest_enum_variant wrongly identifying the second largest variant.
Rustup
This needs a review this time. Especially 521bf8f0fa cc `@camsteffen` I think this is necessary now, because `itertools` is no longer a dependency of `clippy_utils` and therefore this path can't be found 🤔
( I forgot about the sync last week. I should get to document this process better, so other people can do it when I'm not around )
changelog: none
Don't lint `suspicious_else_formatting` inside proc-macros
fixes: #7650
I'll add a test for this one soon.
changelog: Don't lint `suspicious_else_formatting` inside proc-macros
Expand box_vec lint to box_collection
fixed#7451
changelog: Expand `box_vec` into [`box_collection`], and have it error on all sorts of boxed collections
Change `while_let_on_iterator` suggestion to use `by_ref()`
It came up in the discussion #7659 that suggesting `iter.by_ref()` is a clearer suggestion than `&mut iter`. I personally think they're equivalent, but if `by_ref()` is clearer to people then that should be the suggestion.
changelog: Change `while_let_on_iterator` suggestion when using `&mut` to use `by_ref()`
New lint: `same_name_method`
changelog: ``[`same_name_method`]``
fix: https://github.com/rust-lang/rust-clippy/issues/7632
It only compares a method in `impl` with another in `impl trait for`
It doesn't lint two methods in two traits.
I'm not sure my approach is the best way. I meet difficulty in other approaches.
Improve accuracy of `mut_key`
Fixes#6745.
Whilst writing the tests for this, I noticed what I believe is a false negative (the code in `@xFrednet's` [comment](https://github.com/rust-lang/rust-clippy/issues/6745#issuecomment-909658267) doesn't trigger the lint). Currently the tests contain a case for this (which is blatantly ignored), but I'm not at all sure how to implement this (since the lint currently behaves completely differently for ADTs). I'm not sure what should be done - on the one hand the extra test cases are misleading, but on the other hand they don't cause much harm and would save effort for anyone fixing that false negative.
---
changelog: Improve accuracy of `clippy::mutable_key_type`.
Target directory cleanup
changelog: none
* .cargo/config now has `target-dir` specified so that it is inherited by child projects. The target directory needs to be shared with clippy_dev, but not necessarily at the project root. (cc #7625)
* Uses `std::env::current_exe` (and its parent directories) whenever possible
* `CLIPPY_DRIVER_PATH` and `TARGET_LIBS` are no longer required from rustc bootstrap (but `HOST_LIBS` still is). These can be removed from the rustc side after merging.
* `CLIPPY_DOGFOOD` and the separate target directory are removed. This was originally added to mitigate #7343.
r? `@flip1995`
