With rust-lang#70166 merged, `RangeInclusive` now derives `PartialEq` and `Eq`, implementing structural equality and as a side effect the range is now usable with const generics, closing rust-lang#70155.

A test is added to avoid a change to the private fields or the equality implementation of the range from subtly reverting rust-lang#70155.

…Const

In addition to the regression test of `RangeInclusive` for rust-lang#70155, now all range types are checked for usability within const generics:

- `RangeFrom`
- `RangeFull`
- `RangeToInclusive`
- `RangeTo`
- `Range`

The test are moved from `test\ui\const-generics\issues\issue-70155` to `test\ui\const-generics\std\range` in anticipation of future similar tests for std types.

Merge tests to a single test file.

This is needed since `middle::cstore` defines another type named
`DepKind`, and we should not rely on shadowing to get the right one.

Move the dep_graph construction to a dedicated crate.

The interface for librustc consists in two traits: `DepKind` and `DepContext`.

The `DepKind` is the main interface. It allows to probe properties of the dependency.
As before, `DepNode` is the pair of a `DepKind` object and a hash fingerprint.

The `DepContext` takes the place of the `TyCtxt`, and handles communication with the query engine.

The use of the `ImplicitCtxt` through `ty::tls` is done through the `DepKind` trait.
This may not be the best choice, but it seemed like the simplest.

Replace some desc logic in librustc_lint with article_and_desc

r? @eddyb @Centril @matthewjasper

Followup to rust-lang#69674

Blocked on rust-lang#69498

Evaluate repeat expression lengths as late as possible

Fixes rust-lang#68567

r? @varkor

…op-detector, r=RalfJung

Remove const eval loop detector

Now that there is a configurable instruction limit for CTFE (see rust-lang#67260), we can replace the loop detector with something much simpler. See rust-lang#66946 for more discussion about this. Although the instruction limit is nightly-only, the only practical way to reach the default limit uses nightly-only features as well (although CTFE will still execute code using such features inside an array initializer on stable).

This will at the very least require a crater run, since it will result in an error wherever the "long running const eval" warning appeared before. We may need to increase the default for `const_eval_limit` to work around this.

Resolves rust-lang#54384 cc rust-lang#49980
r? @oli-obk cc @RalfJung

Improve E0308 error message wording

Hi folks,

I made [a post on Reddit](https://old.reddit.com/r/rust/comments/fmi11x/consider_linting_rusts_documentationerror_text/) about how (IMO) the docs/error messages can be a bit intimidating, one thing led to another, and I was encouraged to submit a Pull Request if I felt I could re-phrase the error message that I used as an example.

So that's this Pull Request. Open to any feedback or style changes, and I understand this is subjective.

(On another note: I am happy to see [this message was recently improved](rust-lang#69139) in `master`, so it's already better than it is in stable Rust 1.42.0.)

Ideally the last sentence could be split into at least two: [sentence explaining the inferred type.] [Sentence explaining explicit type.] [Sentence that summarizes that "this is bad," and why.]

But I'm not sure how to do so; I'm wary of writing something that turns out to be technically incorrect.

…r=estebank

Fix invalid suggestion on `&mut` iterators yielding `&` references

Fixes rust-lang#69789.

rustc suggested an invalid code when `&` reference from `&mut` iterator is mutated. The compiler knew we're mutating a value behind `&` reference, but as the assignment RHS is from desugaring, it could only see the iterator expression from source and inserted `mut` there.

r? @estebank

…k,wesleywiser

get rid of ConstPropUnsupported; use ZST marker structs instead

This gets rid of yet another machine-specific error variant.

r? @oli-obk

…r=nikomatsakis

Remove `ReClosureBound`

We now substitute external names for regions in the query response.

r? @nikomatsakis

…-obk

Add regression test for rust-lang#70155.

With rust-lang#70166 merged, `RangeInclusive` now derives `PartialEq` and `Eq`, implementing structural equality and as a side effect the range is now usable with const generics, closing rust-lang#70155.

As per [rust-lang#70166 (comment)](rust-lang#70166 (comment)) a test is added to avoid a change to the private fields or the equality implementation of the range from subtly reverting rust-lang#70155.

…r=Centril

Account for bad placeholder types in where clauses

Fix rust-lang#70291. Follow up to rust-lang#69148.

…an-DPC

Clean up E0452 explanation

r? @Dylan-DPC