And make it more uniform with other macros.
By merging placeholders for future derives' outputs into the derive container's output fragment early.

Reciprocal throughput is improved from 2.3 to 1.7.
https://godbolt.org/z/ROMiX6

IntoStringError only implemented Error::cause, which is
deprecated. This implemements Error::source instead.
Error::cause will still work as before, thanks to the default
implementation.

The value names are used when reporting issues found by address
sanitizer or memory sanitizer. Avoid discarding names when those
sanitizers are enabled, unless explicitly requested to do otherwise.

I noticed that in documentation to `Any` trait the old trait object syntax is used, which could be confusing for newcomers, since we generally recommend using `dyn Trait` instead of just `Trait`. This PR changes the documentation comment, so that it uses `&dyn Any`, `&mut dyn Any` and `Box<dyn Any>`, correspondingly.

Co-Authored-By: Jonas Schievink <jonasschievink@gmail.com>

Split non-CAS atomic support off into target_has_atomic_load_store

This PR implements my proposed changes in rust-lang#32976 (comment) by removing `target_has_atomic = "cas"` and splitting `target_has_atomic` into two separate `cfg`s:

* `target_has_atomic = 8/16/32/64/128`: This indicates the largest width that the target can atomically CAS (which implies support for all atomic operations).
* ` target_has_atomic_load_store = 8/16/32/64/128`: This indicates the largest width that the target can support loading or storing atomically (but may not support CAS).

cc rust-lang#32976

r? @alexcrichton

vxWorks: implement get_path() and get_mode() for File fmt::Debug

…hewjasper

expand: Simplify expansion of derives

And make it more uniform with other macros.
This is done by merging placeholders for future derives' outputs into the derive container's output fragment early (addressing FIXMEs from rust-lang#63667).

Also, macros with names starting with `_` are no longer reported as unused, in accordance with the usual behavior of `unused` lints.

r? @matthewjasper or @mark-i-m

improve performance of signed saturating_mul

Reciprocal throughput is improved from 2.3 to 1.7. https://godbolt.org/z/ROMiX6

Fixes rust-lang#65309.

Fix typo in task::Waker

fixes  rust-lang#65323

in `libstd/error.rs` there are a few mentions of `trait@Send` and `trait@Sync`. Are they wrong as well?

nounwind tests and cleanup

This is a follow-up to @pnkfelix' rust-lang#65020. In particular it adds some tests as @nagisa  asked. It also does a cleanup that the original PR omitted to reduce backporting risks.

I hope I finally managed to write an uncontroversial PR in this area. ;) This should not change any behavior, just test it better.

Fix #[unwind(abort)] with Rust ABI

Fixes rust-lang#63883.

syntax: consolidate function parsing in item.rs

Extracted from rust-lang#65324.

r? @estebank

…bluss

Implement Error::source on IntoStringError + Remove superfluous cause impls

IntoStringError only implemented `Error::cause`, which is deprecated. This implemements `Error::source` instead.
`Error::cause` will still work as before, thanks to the default implementation.

I think this was the only/last `Error` impl in the standard library to have a cause, but not a source.

…rkor

Don't discard value names when using address or memory sanitizer

The value names are used when reporting issues found by address
sanitizer or memory sanitizer. Avoid discarding names when those
sanitizers are enabled, unless explicitly requested to do otherwise.

Add `dyn` to `Any` documentation

I noticed that in documentation to `Any` trait the old trait object syntax is used, which could be confusing for newcomers, since we generally recommend using `dyn Trait` instead of just `Trait`. This PR changes the documentation comment, so that it uses `&dyn Any`, `&mut dyn Any` and `Box<dyn Any>`, correspondingly.

Fix typo in docs for `Rc`

r? @czipperz