Rollup merge of rust-lang#86919 - ehuss:update-books, r=ehuss

Update books

## nomicon

8 commits in b9ca313e687c991223e23e5520529815dc281205..7a13537f96af4b9b8e3ea296d6e5c3c7ab72ce9f
2021-06-22 12:02:20 -0400 to 2021-07-05 23:34:47 -0400
- Apply review comments
- Fix some style issues
- Move the list of coercions to the reference
- Add an example that shows the null-pointer opt does not happen
- Remove casting list from the nomicon (rust-lang/nomicon#287)
- Audit `ignore` annotations (rust-lang/nomicon#288)
- rename typo "lifetime" to "reference" (rust-lang/nomicon#286)
- Add an incomplete warning to the top page (rust-lang/nomicon#274)

## reference

7 commits in d9699fa8f3186440fdaadd703d63d8d42322c176..ab60513a3a5a0591e237fddff5d027a982648392
2021-06-21 12:23:10 -0700 to 2021-07-05 08:27:31 -0700
- fix grammar in Expressions (rust-lang/reference#1057)
- fix comment in function parameter drop scope example (rust-lang/reference#1056)
- fix typo in macro-ambiguity.md (rust-lang/reference#1058)
- Mention (negative) infinity values on float-to-int casting (rust-lang/reference#1054)
-  (rust-lang/reference#841)
- Missing TypeParamBounds in TypeAlias (rust-lang/reference#1036)
- Be more precise about array offset in type layouts (rust-lang/reference#1034)

## book

34 commits in 55a26488ddefc8433e73a2e8352d70f7a5c7fc2b..a90f07f1e9a7fc75dc9105a6c6f16d5c13edceb0
2021-05-09 12:03:18 -0500 to 2021-07-05 14:43:12 -0400
- Clarify ?Sized syntax. Fixes rust-lang/book#2422.
- Add some notes that macros are different than functions
- Break up a long sentence. Fixes rust-lang/book#2329.
- Further clarify and make consistent the reference to deref coercion
- Update ch04-03-slices.md
- add usage for `String` reference
- Update ch15-02-deref.md (rust-lang/book#2780)
- Remove claim about performance of i32
- Reword to avoid awkward pluralization
- Make the link to the reference relative
- Merge remote-tracking branch 'origin/pr/2753'
- Reword number of library crates a package contains (rust-lang/book#2750)
- Clarify explanation of why you can test private functions; add link
- Merge remote-tracking branch 'origin/pr/2743'
- Fix code hiding that I broke in eb60fedc9
- Link to the exact later section we're talking about
- improve cross-references for newtype pattern
- ch12-05, listing 12-20: Add missing "does not compile" warning (rust-lang/book#2731)
- cargo format
- Merge remote-tracking branch 'origin/pr/2724'
- Remove ordinal numbers and only refer to indexes to avoid confusion
- Let's mention the former and current authors of tlborm.
- Update tlborm link to point to Veykril's up-to-date version (rust-lang/book#2722)
- Merge remote-tracking branch 'origin/pr/2720'
- Describe the ferris pictures in the alt text
- Merge remote-tracking branch 'origin/pr/2707'
- Reword ... explanation to include the word deprecated, list that first
- Precise that the `...` inclusive range pattern has been replaces (rust-lang/book#2714)
-  (rust-lang/book#2696)
- fix typo: missing "type" after generic (rust-lang/book#2777)
-  (rust-lang/book#2709)
- Remove sentence about how Rust used to be
- Fix a potentially confusing statement about static lifetimes of static variables. (rust-lang/book#2692)
- Replace 'which'. (rust-lang/book#2663)

## rust-by-example

2 commits in 805e016c5792ad2adabb66e348233067d5ea9f10..028f93a61500fe8f746ee7cc6b204ea6c9f42935
2021-05-20 17:08:34 -0300 to 2021-07-06 06:28:53 -0300
- Fix a couple of typos in the `integration_testing.md` file (rust-lang/rust-by-example#1448)
- Fix Structures type list (rust-lang/rust-by-example#1446)

## rustc-dev-guide

13 commits in fe34bed..60e2825
2021-06-21 21:50:12 +0200 to 2021-07-05 11:21:03 -0400
- Fixed typos in inline code
- Document lang items (rust-lang/rustc-dev-guide#1119)
- More specifics on what future-incompatible lints are used for
- Fix line lens
- Update information on lints particularly on future-incompatible
- Update section of lint store
- Update around half of the January 2021 date references (rust-lang/rustc-dev-guide#1155)
- Create issues for many TODOs (rust-lang/rustc-dev-guide#1163)
- Links from rustc-dev-guide to std-dev-guide (rust-lang/rustc-dev-guide#1152)
- Document how to mark features as incomplete (rust-lang/rustc-dev-guide#1151)
- Remove requests or suggestions about rebase and fixup contradictory to rust-highfive bot comment (rust-lang/rustc-dev-guide#1111)
- Generate glossary table correctly (rust-lang/rustc-dev-guide#1146)
- Correct the wrong serial number (rust-lang/rustc-dev-guide#1147)

## edition-guide

3 commits in c74b2a0d6bf55774cf15d69f05dfe05408b8f81a..5d57b3832f8d308a9f478ce0a69799548f27ad4d
2021-06-14 10:48:27 -0700 to 2021-07-05 10:33:32 +0200
- Add more info for warnings promoted to errors (rust-lang/edition-guide#247)
- Create triagebot.toml
- Clarify snippets in 2021 panic docs. (rust-lang/edition-guide#245)

## embedded-book

1 commits in cbec77fbd8eea0c13e390dd9eded1ae200e811d1..506840eb73b0749336e1d5274e16d6393892ee82
2021-06-10 06:26:32 +0000 to 2021-06-24 00:01:32 +0000
- Update book to track quickstart changes  (rust-embedded/book#296)

Author: JohnTitor