Rollup merge of rust-lang#146339 - rustbot:docs-update, r=ehuss

Update books

## rust-lang/nomicon

1 commits in 57ed4473660565d9357fcae176b358d7e8724ebf..f17a018b9989430967d1c58e9a12c51169abc744
2025-09-05 22:46:58 UTC to 2025-09-05 22:46:58 UTC

- Add missing "C" ABI to FFI example code (rust-lang/nomicon#501)

## rust-lang/reference

7 commits in 89f67b3c1b904cbcd9ed55e443d6fc67c8ca2769..b3ce60628c6f55ab8ff3dba9f3d20203df1c0dee
2025-09-05 20:14:36 UTC to 2025-08-26 20:17:24 UTC

- Ensure all lexical elements are SCREAMING_CASE (rust-lang/reference#1990)
- Link out to the notation from grammar summary (rust-lang/reference#1989)
- Or-patterns are extending (rust-lang/reference#1975)
- Specify lifetime extension of `match` arms and `if` consequent/`else` block tail expressions (rust-lang/reference#1981)
- clean up and properly test temporary lifetime extension in doctests (rust-lang/reference#1979)
- Update `cold` and `inline` to use the attribute template (rust-lang/reference#1907)
- Pluralize "syntax diagrams" (rust-lang/reference#1977)

## rust-lang/rust-by-example

1 commits in ad27f82c18464525c761a4a8db2e01785da59e1f..dd26bc8e726dc2e73534c8972d4dccd1bed7495f
2025-09-04 22:33:29 UTC to 2025-09-04 22:33:29 UTC

- Fix drop order explanation in trait > drop (rust-lang/rust-by-example#1953)

Author: Zalathar