Change from syntaxy-looking [src] to the plain word "source".

They were stabilized together with `Option::unwrap_unchecked`
in rust-lang#81383.

Signed-off-by: Miguel Ojeda <[email protected]>

Noted in rust-lang#87739 (review),
lang_items::extract no longer needs to take a closure.

…pointee, r=jackh726

Normalize struct tail type when checking Pointee trait

Let's go ahead and implement the FIXMEs by properly normalizing the struct-tail type when satisfying a Pointee obligation. This should fix the ICE when we try to calculate a layout depending on `<Ty as Pointee>::Metadata` later.
Fixes rust-lang#92128
Fixes rust-lang#92577

Additionally, mark the obligation as ambiguous if there are any infer types in that struct-tail type. This has the effect of causing `<_ as Pointee>::Metadata` to be properly replaced with an infer variable ([here](https://github.com/rust-lang/rust/blob/master/compiler/rustc_trait_selection/src/traits/project.rs#L813)) and registered as an obligation... this turns out to be very important in unifying function parameters with formals that are assoc types.

Fixes rust-lang#91446

…line-removal, r=camelid

Fix invalid removal of newlines from doc comments

Fixes rust-lang#91201.

Before:

![Screenshot from 2021-12-28 17-02-11](https://user-images.githubusercontent.com/3050060/147585187-c8e67531-c1b4-457d-9d30-d5b44bf91fea.png)

After:

![Screenshot from 2021-12-28 17-02-25](https://user-images.githubusercontent.com/3050060/147585190-30aa0398-1fc7-4fe7-9e8b-5c475d4f9613.png)

r? `@camelid`

Make source links look cleaner

Change from syntaxy-looking [src] to the plain word "source".

Change the syntaxy-looking `[-]` at the top of the page to say "collapse".

Reduce opacity of rightside content.

Part of rust-lang#59851

r? `@GuillaumeGomez`

Demo: https://rustdoc.crud.net/jsha/source-link-2/std/string/struct.String.html

[Discussed on Zulip](https://rust-lang.zulipchat.com/#narrow/stream/266220-rustdoc/topic/display.20of.20source.20link).

…-const-expr, r=oli-obk

Normalize generator-local types with unevaluated constants

Normalize generator-interior types in addition to (i.e. instead of just) erasing regions, since sometimes we collect types with unevaluated const exprs.

Fixes rust-lang#84737
Fixes rust-lang#88171
Fixes rust-lang#92091
Fixes rust-lang#92634
Probably also fixes rust-lang#73114, but that one has no code I could test. It looks like it's the same issue, though.

Release notes: add `Result::unwrap_{,err_}unchecked`

They were stabilized together with `Option::unwrap_unchecked`
in rust-lang#81383.

Signed-off-by: Miguel Ojeda <[email protected]>

…etrochenkov

Clean up lang_items::extract

Noted in rust-lang#87739 (review),
lang_items::extract no longer needs to take a closure.

update miri

Fixes rust-lang#92691
r? `@ghost`