Auto merge of #61529 - ehuss:update-books, r=GuillaumeGomez

Update books

## reference

2 commits in 862b669..f8ae436
2019-05-04 23:41:35 -0700 to 2019-05-31 14:59:12 +0200
- Document that literals with any suffixes are valid as tokens (rust-lang/reference#612)
- Fix example code of derive macro (rust-lang/reference#611)

## book

2 commits in 29fe982990e43b9367be0ff47abc82fb2123fd03..62a8c6f25fbd981c80a046f3b04be9684749af3b
2019-05-15 17:48:40 -0400 to 2019-05-28 15:48:23 -0400
- Remove snapshots checked in layout
- Remove snapshots that I've approved in layout

## rust-by-example

5 commits in 811c697b232c611ed754d279ed20643a0c4096f6..18566f4dedc3ef5bf61f5f85685d5966db99cc11
2019-04-28 18:56:42 -0300 to 2019-05-30 19:23:24 -0300
- Fixed wording in the `Seconds` struct description. (rust-lang/rust-by-example#1195)
- Fix usage of the word "elision" (rust-lang/rust-by-example#1191)
- Reword "Flow Control" to "Flow of Control" (rust-lang/rust-by-example#1190)
- Copy edits to chapter 1 (rust-lang/rust-by-example#1189)
- Fix typo in a mod/visibility.md (rust-lang/rust-by-example#1188)

## rustc-guide

9 commits in 3cb727b..3ac9cfc
2019-05-07 09:53:32 -0500 to 2019-06-02 19:36:58 -0500
- Update information about debuginfo configuration
- fix long line
- Fixed misspelling
- Add more info subsection with links to forge and rustc api docs (rust-lang/rustc-dev-guide#324)
- Renamed the file and title of the diagnostics chapter.
- Added rustc phases diagram and explanation
- Mention running tests for subdirectories
- Fixed links broken by merging chalks rules and solve
- Add documentation about profile-guided optimization.

## embedded-book

1 commits in 9858872bd1b7dbba5ec27dc30d34eba00acd7ef9..f0c75b75f9c18537b78f5d17c1015247e9a49c86
2019-05-02 18:56:54 +0000 to 2019-06-03 10:49:02 +0000
- Qemu md changes  (rust-embedded/book#193)

Author: bors