Rollup merge of #64580 - ehuss:update-books, r=ehuss

Update books

## book

24 commits in 7ddc46460f09a5cd9bd2a620565bdc20b3315ea9..871416b85c1a73717d65d6f4a9ea29e5aef3db0e
2019-06-27 09:50:36 -0400 to 2019-09-16 09:46:20 -0400
- Ch16-2 add missing Ferris (rust-lang/book#2033)
- Update version mentioned on the front page
- Update error messages (rust-lang/book#1737)
- Update version of Rust used to 1.37
- Replace Cargo docs link with a more specific link (rust-lang/book#2066)
- Added missing await reserved keyword (rust-lang/book#2064)
- add does_not_compile for a snippet (rust-lang/book#2056)
- Added second missing dyn (rust-lang/book#2046)
- Removed unnecessary & in function call (rust-lang/book#2038)
- Printing non-Display structs is a *compile* error (rust-lang/book#2031)
- Update Readme mdBook version to match linked file (rust-lang/book#2012)
- Update loose mdbook version reference (rust-lang/book#2003)
- Added a bullet point to have list of things unsafe allows for match u… (rust-lang/book#1993)
- Rewrote a confusing sentence (rust-lang/book#1986)
- Replace deprecated `...` range syntax with `..=` (rust-lang/book#1977)
- correct wording for integration test doc (rust-lang/book#1971)
- Mark the dangle function as does_not_compile (rust-lang/book#1965)
- Add more words to the quote from the actual Go documentation (rust-lang/book#1960)
- Remove unused import in lfp (rust-lang/book#1944)
- A small typo? (rust-lang/book#1931)
- Make the code not compile to match the text (rust-lang/book#1926)
- Ferris does-not-compile added (ch9.2) (rust-lang/book#1925)
- ch07 - remove note regarding use and relative path (rust-lang/book#1820)
- tweak opening paragraph of deref coercions (rust-lang/book#1749)

## rust-by-example

9 commits in e76be6b2dc84c6a992e186157efe29d625e29b94..67cfbf31df880728dcf7cb35b15b028ec92caf31
2019-09-03 07:42:26 -0300 to 2019-09-18 09:36:40 -0300
- Fix rust-lang/rust-by-example#90: Add supertraits and Fully Qualified syntax (rust-lang/rust-by-example#1259)
- Fix some broken links. (rust-lang/rust-by-example#1258)
- Fix rust-lang/rust-by-example#1253: Document enum type aliases (rust-lang/rust-by-example#1255)
- Inline code in some new/changed chapters (rust-lang/rust-by-example#1254)
- fix rust-lang/rust-by-example#1067: explain that unit tests can return Result<()> (rust-lang/rust-by-example#1252)
- Fix rust-lang/rust-by-example#1060: add page on Impl Trait (rust-lang/rust-by-example#1251)
- Fix rust-lang/rust-by-example#1053: Added a page about the dyn keyword (rust-lang/rust-by-example#1249)
- Fix rust-lang/rust-by-example#1110: add examples of ? and Option (rust-lang/rust-by-example#1250)
- fix 1037: add the TryFrom chapter back in (rust-lang/rust-by-example#1247)
diff --git a/src/doc/book b/src/doc/book
index 7ddc464..871416b 160000
--- a/src/doc/book
+++ b/src/doc/book
@@ -1 +1 @@
-Subproject commit 7ddc46460f09a5cd9bd2a620565bdc20b3315ea9
+Subproject commit 871416b85c1a73717d65d6f4a9ea29e5aef3db0e
diff --git a/src/doc/rust-by-example b/src/doc/rust-by-example
index e76be6b..67cfbf3 160000
--- a/src/doc/rust-by-example
+++ b/src/doc/rust-by-example
@@ -1 +1 @@
-Subproject commit e76be6b2dc84c6a992e186157efe29d625e29b94
+Subproject commit 67cfbf31df880728dcf7cb35b15b028ec92caf31