Auto merge of rust-lang#136918 - GuillaumeGomez:rollup-f6h21gg, r=GuillaumeGomez

Rollup of 8 pull requests

Successful merges:

 - rust-lang#134981 ( Explain that in paths generics can't be set on both the enum and the variant)
 - rust-lang#136698 (Replace i686-unknown-redox target with i586-unknown-redox)
 - rust-lang#136767 (improve host/cross target checking)
 - rust-lang#136829 ([rustdoc] Move line numbers into the `<code>` directly)
 - rust-lang#136875 (Rustc dev guide subtree update)
 - rust-lang#136900 (compiler: replace `ExternAbi::name` calls with formatters)
 - rust-lang#136913 (Put kobzol back on review rotation)
 - rust-lang#136915 (documentation fix: `f16` and `f128` are not double-precision)

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

Diff for: std/src/f128.rs

@@ -1,4 +1,4 @@
-//! Constants for the `f128` double-precision floating point type.
+//! Constants for the `f128` quadruple-precision floating point type.
 //!
 //! *[See also the `f128` primitive type](primitive@f128).*
 //!

Diff for: std/src/f16.rs

@@ -1,4 +1,4 @@
-//! Constants for the `f16` double-precision floating point type.
+//! Constants for the `f16` half-precision floating point type.
 //!
 //! *[See also the `f16` primitive type](primitive@f16).*
 //!