When encountering an unsatisfied trait bound, if there are no other
suggestions, mention all the types that *do* implement that trait:

```
error[E0277]: the trait bound `f32: Foo` is not satisfied
  --> $DIR/impl_wf.rs:22:6
   |
LL | impl Baz<f32> for f32 { }
   |      ^^^^^^^^ the trait `Foo` is not implemented for `f32`
   |
   = help: the following other types implement trait `Foo`:
             Option<T>
             i32
             str
note: required by a bound in `Baz`
  --> $DIR/impl_wf.rs:18:31
   |
LL | trait Baz<U: ?Sized> where U: Foo { }
   |                               ^^^ required by this bound in `Baz`
```

Mention implementers of traits in `ImplObligation`s.

Do not mention other `impl`s for closures, ranges and `?`.

…ied-trait, r=davidtwco

Mention implementers of unsatisfied trait

When encountering an unsatisfied trait bound, if there are no other
suggestions, mention all the types that *do* implement that trait:

```
error[E0277]: the trait bound `f32: Foo` is not satisfied
  --> $DIR/impl_wf.rs:22:6
   |
LL | impl Baz<f32> for f32 { }
   |      ^^^^^^^^ the trait `Foo` is not implemented for `f32`
   |
   = help: the trait `Foo` is implemented for `i32`
note: required by a bound in `Baz`
  --> $DIR/impl_wf.rs:18:31
   |
LL | trait Baz<U: ?Sized> where U: Foo { }
   |                               ^^^ required by this bound in `Baz`
```
```
error[E0277]: the trait bound `u32: Foo` is not satisfied
  --> $DIR/associated-types-path-2.rs:29:5
   |
LL |     f1(2u32, 4u32);
   |     ^^ the trait `Foo` is not implemented for `u32`
   |
   = help: the trait `Foo` is implemented for `i32`
note: required by a bound in `f1`
  --> $DIR/associated-types-path-2.rs:13:14
   |
LL | pub fn f1<T: Foo>(a: T, x: T::A) {}
   |              ^^^ required by this bound in `f1`
```

Suggest dereferencing in more cases.

Fix rust-lang#87437, fix rust-lang#90970.

explicitly distinguish pointer::addr and pointer::expose_addr

``@bgeron`` pointed out that the current docs promise that `ptr.addr()` and `ptr as usize` are equivalent. I don't think that is a promise we want to make. (Conceptually, `ptr as usize` might 'escape' the provenance to enable future `usize as ptr` casts, but `ptr.addr()` dertainly does not do that.)

So I propose we word the docs a bit more carefully here. ``@Gankra`` what do you think?

Fix late-bound ICE in `dyn` return type suggestion

This fixes the root-cause of the attached issues -- the root problem is that we're using the return type from a signature with late-bound instead of early-bound regions. The change on line 1087 (`let Some(liberated_sig) = typeck_results.liberated_fn_sigs().get(fn_hir_id) else { return false; };`) makes sure we're grabbing the _right_ return type for this suggestion to check the `dyn` predicates with.

Fixes rust-lang#91801
Fixes rust-lang#91803

This fix also includes some drive-by changes, specifically:

1. Don't suggest boxing when we have `-> dyn Trait` and are already returning `Box<T>` where `T: Trait` (before we always boxed the value).
2. Suggestion applies even when the return type is a type alias (e.g. `type Foo = dyn Trait`). This does cause the suggestion to expand to the aliased type, but I think it's still beneficial.
3. Split up the multipart suggestion because there's a 6-line max in the printed output...

I am open to splitting out the above changes, if we just want to fix the ICE first.

cc: ```@terrarier2111``` and rust-lang#92289

interpret: remove MemoryExtra in favor of giving access to the Machine

The Miri PR for this is upcoming.

r? ``@oli-obk``

…Jung

Update `NonNull` pointer provenance methods' documentation

 - Add links to equivalent methods on raw pointers

…locks, r=davidtwco

Refactor: remove unnecessary nested blocks

`CandidateSource::XCandidate` -> `CandidateSource::X`