Rollup merge of rust-lang#89378 - ehuss:update-books, r=ehuss

Update books

## nomicon

1 commits in fe6227eb3c8533200c52dffa42ef1b6f2f02c40e..2747c4bb2cbc0639b733793ddb0bf4e9daa2634e
2021-08-31 05:42:38 +0900 to 2021-09-19 17:33:32 +0900
- Clarify a bit of wording (rust-lang/nomicon#310)

## reference

2 commits in 0e5ed7a4bec065f0cc18c35d1c904639e095314d..13747275bd14c2d2b453100498532f9ae5504769
2021-08-29 17:33:21 +0900 to 2021-09-24 17:44:04 +0900
-  (rust-lang/reference#1087)
- Document RangeFrom patterns (rust-lang/reference#900)

## book

4 commits in fcb5e0ea68112d85a1d29a7a7335978ef2a02181..eb1282ec444db94055fa9531b6f3f803e86bb382
2021-08-31 21:26:19 -0400 to 2021-09-16 21:17:09 -0400
- Rust 1.55 (rust-lang/book#2890)
- Chapter 3.3: Remove unused variable (rust-lang/book#2877)
- Appendix (operators and symbols): remove extra space (rust-lang/book#2876)
- Chapter 17.1: add missing comma (rust-lang/book#2867)

## rust-by-example

2 commits in 9d4132b56c4999cd3ce1aeca5f1b2f2cb0d11c24..28aca4a36962c709bce301c03114b5589381dfb8
2021-09-14 06:56:00 -0300 to 2021-09-25 08:19:51 -0300
- fix formatting (rust-lang/rust-by-example#1463)
- involving === verb, involved === adjective (rust-lang/rust-by-example#1461)

## rustc-dev-guide

7 commits in 9198465..d1f03cb
2021-09-12 11:50:44 -0500 to 2021-09-24 12:00:29 +0900
- Fix a typo on closure.md (rust-lang/rustc-dev-guide#1218)
- const generics update
- s/--blessed/--bless/
- Make indentation consistent in example vscode config file
- Suggests `--edition=2018` argument when using stage0/bin/rustfmt directly
- `ty::Unevaluated`: dealing with unused substs (rust-lang/rustc-dev-guide#1190)
- Parallel codegen (rust-lang/rustc-dev-guide#1206)

Author: ehuss