[rustdoc] Box ItemKind to reduce the size of `Item`
This brings the size of `Item` from
```
[src/librustdoc/lib.rs:103] std::mem::size_of::<Item>() = 536
```
to
```
[src/librustdoc/lib.rs:103] std::mem::size_of::<Item>() = 136
```
This is an alternative to https://github.com/rust-lang/rust/pull/79967; I don't think it makes sense to make both changes.
Helps with #79103.
Rollup of 11 pull requests
Successful merges:
- #80383 (clarify wrapping ptr arithmetic docs)
- #80390 (BTreeMap: rename the area access methods)
- #80393 (Add links to the source for the rustc and rustdoc books.)
- #80398 (Use raw version of align_of in rc data_offset)
- #80402 (Document `InferTy` & co.)
- #80403 (fix: small typo error in chalk/mod.rs)
- #80410 (rustdoc book: fix example)
- #80419 (Add regression test for #80375)
- #80430 (Add "length" as doc alias to len methods)
- #80431 (Add "chr" as doc alias to char::from_u32)
- #80448 (Fix stabilization version of deque_range feature.)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
NatVis files describe how to display types in some Windows debuggers,
such as Visual Studio, WinDbg, and VS Code.
This commit makes several improvements:
* Adds visualizers for Rc<T>, Weak<T>, and Arc<T>.
* Changes [size] to [len], for consistency with the Rust API.
Visualizers often use [size] to mirror the size() method on C++ STL
collections.
* Several visualizers used the PVOID and ULONG typedefs. These are part
of the Windows API; they are not guaranteed to always be defined in a
pure Rust DLL/EXE. I converted PVOID to `void*` and `ULONG` to
`unsigned long`.
* Cosmetic change: Removed {} braces around the visualized display
for `Option` types. They now display simply as `Some(value)` or
`None`, which reflects what is written in source code.
* The visualizer for `alloc::string::String` makes assumptions about
the layout of `String` (it casts `String*` to another type), rather
than using symbolic expressions. This commit changes the visualizer
so that it simply uses symbolic expressions to access the string
data and string length.
Add "chr" as doc alias to char::from_u32
Many programming languages provide a function called `chr` - Perl, Python, PHP, Visual Basic, SQL. This change makes `char::from_u32` easier to discover in the documentation.
`ord` is not added as its name conflicts with `Ord` trait, and it's not exactly clear what it could point to (`<u32 as From<char>>::from`?). I don't think it's exactly necessary, as `char::from_u32` documentation page says you can do reverse conversion with `as` operator anyway.
Add "length" as doc alias to len methods
Currently when searching for `length` there are no results: https://doc.rust-lang.org/std/?search=length. This makes `len` methods appear when searching for `length`.
