Auto merge of #77224 - RalfJung:rollup-hdvb96c, r=RalfJung

Auto merge of #77224 - RalfJung:rollup-hdvb96c, r=RalfJung

Rollup of 12 pull requests

Successful merges:

 - #75454 (Explicitly document the size guarantees that Option makes.)
 - #76631 (Add `x.py setup`)
 - #77076 (Add missing code examples on slice iter types)
 - #77093 (merge `need_type_info_err(_const)`)
 - #77122 (Add `#![feature(const_fn_floating_point_arithmetic)]`)
 - #77127 (Update mdBook)
 - #77161 (Remove TrustedLen requirement from BuilderMethods::switch)
 - #77166 (update Miri)
 - #77181 (Add doc alias for pointer primitive)
 - #77204 (Remove stray word from `ClosureKind::extends` docs)
 - #77207 (Rename `whence` to `span`)
 - #77211 (Remove unused #[allow(...)] statements from compiler/)

Failed merges:

 - #77170 (Remove `#[rustc_allow_const_fn_ptr]` and add `#![feature(const_fn_fn_ptr_basics)]`)

r? `@ghost`