rustdoc: remove redundant `#help-button` CSS
When the separate top and bottom styles were added in cd3f4da244578a2ab4d17d10016c61b9191b21e4, some of the CSS rules were needlessly duplicated.
The `text-align: initial` rule on `.side-by-side` was always redundant, since the rules that centered the text were set on children, not parents.
session: remove now-unnecessary lint `#[allow]`s
In #101230, the internal diagnostic migration lints - `diagnostic_outside_of_impl` and `untranslatable_diagnostic` - were modified so that they wouldn't trigger on functions annotated with `#[rustc_lint_diagnostics]`. However, this change has to make it into the bootstrap compiler before the `#[allow]` annotations that it aims to remove can be removed, which is possible now that #102051 has landed.
Avoid LLVM-deprecated `Optional::hasValue`
LLVM 15 added `Optional::has_value`, and LLVM `main` (16) has deprecated
`hasValue`. However, its `explicit operator bool` does the same thing,
and was added long ago, so we can use that across our full LLVM range of
compatibility.
rustdoc: remove no-op CSS `.srclink { font-weight; font-size }`
When this CSS was added in 34bd2b845b3acd84c5a9bddae3ff8081c19ec5e9, source links were nested below headers.
34bd2b845b/src/librustdoc/html/render.rs (L4015-L4019)
Now, thanks to 458e7219bc2a62f72368279945cfda632a016da1, they are now siblings of headers, and thanks to 270d09dca9aae263671c4d32bbc7cb60dc378af8, they have the same font size that they would've had anyway.
rustdoc: use CSS containment to speed up render
https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Containment
This affected layout a little and required adjustments to the CSS to keep spacing the same. In particular, the margins of adjacent items usually overlap with each other. However, when an item has contain: layout, any margins of child nodes push out the size of the item itself. This was making spacing between items a little too big. To solve that, I removed margins in some places: in particular for certain classes that often occur at the end of a `details.rustdoc-toggle` block, I removed their bottom margin. Generally, the margins provided by the next item down are sufficient.
Also remove an unnecessary margin-top on .code-header.
In particular this helps with the problem that rustdoc in some situations can generate giant HTML pages, which can crash a Chrome tab on typical modern hardware, for instance: `https://docs.rs/iced-x86/1.16.0/iced_x86/code_asm/struct.CodeAssembler.html` (26MB, 409k DOM nodes). This doesn't, of course, universally solve the problem, but it pushes out the boundary of the largest page rustdoc can produce without crashing a browser tab.
Demos:
https://rustdoc.crud.net/jsha/css-contain/std/string/struct.String.html
(warning: giant page, _may_ crash a browser tab) https://rustdoc.crud.net/jsha/css-contain-icedx86/iced_x86/code_asm/struct.CodeAssembler.html
r? `@notriddle`
Stabilize `#![feature(mixed_integer_ops)]`
Tracked and FCP completed in #87840.
````@rustbot```` label +T-libs-api +S-waiting-on-review +relnotes
r? rust-lang/t-libs-api
When the separate top and bottom styles were added in
cd3f4da244578a2ab4d17d10016c61b9191b21e4, some of the CSS rules were
needlessly duplicated.
The `text-align: initial` rule on `.side-by-side` was always redundant, since
the rules that centered the text were set on children, not parents.
https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Containment
This affected layout a little and required adjustments to the CSS to
keep spacing the same. In particular, the margins of adjacent items
usually overlap with each other. However, when an item has contain:
layout, any margins of child nodes push out the size of the item itself.
This was making spacing between items a little too big. To solve that, I
removed margins in some places: in particular for certain classes that
often occur at the end of a `details.rustdoc-toggle` block, I removed
their bottom margin. Generally, the margins provided by the next item
down are sufficient.
Also remove an unnecessary margin-top on .code-header.
