This is adding a migration lint for the current (in the 2021 edition and previous)
to move expr to expr_2021 from expr

Co-Developed-by: Eric Holk
Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>

Co-Developed-by: Eric Holk
Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>

…xpr2024, r=compiler-errors,eholk

migration lint for `expr2024` for the edition 2024

This is adding a migration lint for the current (in the 2021 edition and previous)
to move expr to expr_2021 from expr

Issue rust-lang#123742

I created also a repository to test out the migration https://github.com/vincenzopalazzo/expr2024-cargo-fix-migration

Co-Developed-by: ```@eholk```

…dtolnay

impl FusedIterator and a size hint for the error sources iter

cc tracking issue rust-lang#58520

…e-doc, r=fmease

`#[doc(alias)]`'s doc: say that ASCII spaces are allowed

PR rust-lang#77570 allowed ASCII spaces in doc aliases, but the documentation wasn't updated to say so.

The code checking the aliases:
https://github.com/rust-lang/rust/blob/7fdefb804ec300fb605039522a7c0dfc9e7dc366/compiler/rustc_passes/src/check_attr.rs#L693-L704

```````@rustbot``````` label +A-docs

…-errors

small search graph refactor

small improvements which shouldn't impact behavior.

r? ```````@compiler-errors```````

…-pings, r=lqd

Remove spastorino from SMIR

r? ````@oli-obk````

documentation: update cmake version

Previously discussed here: rust-lang#127531