The flag `--no-stack-check` does not exist:

    $ rustc --no-stack-check
    error: Unrecognized option: 'no-stack-check'. Did you mean `-C no-stack-check`?

This deprecates `-Cinline-threshold` since using it has no effect. This
has been the case since the new LLVM pass manager started being used,
more than 2 years ago.

Co-authored-by: Wedson Almeida Filho <walmeida@microsoft.com>

It might make sense to allow this in the future, if we add values that aren't
mutually exclusive, but for now having multiple coverage attributes on one item
is useless.

This upgrades some warnings to errors, and also catches cases where the
attribute was silently ignored.

…owed items

Signed-off-by: onur-ozkan <work@onurozkan.dev>

This is possible now that inline const blocks are stable; the idea was
even mentioned as an alternative when `uninit_array()` was added:
<rust-lang#65580 (comment)>

> if it’s stabilized soon enough maybe it’s not worth having a
> standard library method that will be replaceable with
> `let buffer = [MaybeUninit::<T>::uninit(); $N];`

Const array repetition and inline const blocks are now stable (in the
next release), so that circumstance has come to pass, and we no longer
have reason to want `uninit_array()` other than convenience. Therefore,
let’s evaluate the inconvenience by not using `uninit_array()` in
the standard library, before potentially deleting it entirely.

…enum-with-debug, r=pnkfelix

Show notice about  "never used" of Debug for enum

Close rust-lang#123068

If an ADT implements `Debug` trait and it is not used, the compiler says a note that indicates intentionally ignored during dead code analysis as [this note](https://github.com/rust-lang/rust/blob/2207179a591f5f252885a94ab014dafeb6e8e9e8/tests/ui/lint/dead-code/unused-variant.stderr#L9).
However this node is not shown for variants that have fields in enum. This PR fixes to show the note.

…, r=pnkfelix

Deprecate no-op codegen option `-Cinline-threshold=...`

This deprecates `-Cinline-threshold` since using it has no effect. This has been the case since the new LLVM pass manager started being used, more than 2 years ago.

Recommend using `-Cllvm-args=--inline-threshold=...` instead.

Closes rust-lang#89742 which is E-help-wanted.

Remove `MaybeUninit::uninit_array()` and replace it with inline const blocks.

\[This PR originally contained the changes in rust-lang#125995 too. See edit history for the original PR description.]

The documentation of `MaybeUninit::uninit_array()` says:

> Note: in a future Rust version this method may become unnecessary when Rust allows [inline const expressions](rust-lang#76001). The example below could then use `let mut buf = [const { MaybeUninit::<u8>::uninit() }; 32];`.

The PR adding it also said: <rust-lang#65580 (comment)>

> if it’s stabilized soon enough maybe it’s not worth having a standard library method that will be replaceable with `let buffer = [MaybeUninit::<T>::uninit(); $N];`

That time has come to pass — inline const expressions are stable — so `MaybeUninit::uninit_array()` is now unnecessary. The only remaining question is whether it is an important enough *convenience* to keep it around.

I believe it is net good to remove this function, on the principle that it is better to compose two orthogonal features (`MaybeUninit` and array construction) than to have a specific function for the specific combination, now that that is possible.

… r=davidtwco

SmartPointer derive-macro

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Possibly replacing rust-lang#123472 for continued upkeep of the proposal rust-lang/rfcs#3621 and implementation of the tracking issue rust-lang#123430.

cc `@Darksonn` `@wedsonaf`

compiletest: make the crash test error message abit more informative

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

…, r=compiler-errors

Ensure we don't accidentally succeed when we want to report an error

This also changes the `DefiningOpaqueTypes::No` to `Yes` without adding tests, as it is solely run on the error path to improve diagnostics. I was unable to provide a test that changes diagnostics, as all the tests I came up with ended up successfully constraining the opaque type and thus succeeding the coercion.

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

cc rust-lang#116652

coverage: Overhaul validation of the `#[coverage(..)]` attribute

This PR makes sweeping changes to how the (currently-unstable) coverage attribute is validated:
- Multiple coverage attributes on the same item/expression are now treated as an error.
- The attribute must always be `#[coverage(off)]` or `#[coverage(on)]`, and the error messages for this are more consistent.
  -  A trailing comma is still allowed after off/on, since that's part of the normal attribute syntax.
- Some places that silently ignored a coverage attribute now produce an error instead.
  - These cases were all clearly bugs.
- Some places that ignored a coverage attribute (with a warning) now produce an error instead.
  - These were originally added as lints, but I don't think it makes much sense to knowingly allow new attributes to be used in meaningless places.
  - Some of these errors might soon disappear, if it's easy to extend recursive coverage attributes to things like modules and impl blocks.

---

One of the goals of this PR is to lay a more solid foundation for making the coverage attribute recursive, so that it applies to all nested functions/closures instead of just the one it is directly attached to.

Fixes rust-lang#126658.

This PR incorporates rust-lang#126659, which adds more tests for validation of the coverage attribute.

`@rustbot` label +A-code-coverage

…r=davidtwco

Suggest inline const blocks for array initialization

rust-lang#126894

Small fixme in core now that NonZero is generic

I doubt I have the rights to, but
`@bors` rollup=always

add @Kobzol to bootstrap team for triagebot

Welcome ``@Kobzol`` !

…piler-errors

Split the lifetimes of `MirBorrowckCtxt`

These lifetimes are sometimes too general and will link things together that are independent. These are a blocker for actually finishing tracking more state (e.g. error tainting) in the diagnostic context handle, and I'd rather land it in its own PR instead of together with functional changes.

Also changes a bunch of named lifetimes to `'_` where they were irrelevant

follow-up to rust-lang#126623