On stable, suggest removing `#![feature]` for features that have been stabilized
I don't know how to test this (https://rust-lang.zulipchat.com/#narrow/stream/182449-t-compiler.2Fhelp/topic/Run.20tests.20without.20enabling.20nightly.20features.3F). I confirmed locally that this gives the
appropriate help with `channel = "beta"`:
```
error[E0554]: `#![feature]` may not be used on the beta release channel
--> src/lib.rs:2:1
|
2 | #![feature(min_const_generics)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove the attribute
|
= help: the feature `min_const_generics` has been stable since 1.51.0 and no longer requires an attribute to enable
error[E0554]: `#![feature]` may not be used on the beta release channel
--> src/lib.rs:3:1
|
3 | #![feature(min_const_generics, min_specialization)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: the feature `min_const_generics` has been stable since 1.51.0 and no longer requires an attribute to enable
error[E0554]: `#![feature]` may not be used on the beta release channel
--> src/lib.rs:4:1
|
4 | #![feature(box_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^
```
Closes https://github.com/rust-lang/rust/issues/83715.
a7aba58e96