Rollup merge of #59754 - ehuss:update-books, r=frewsxcv

Update books

## nomicon

1 commits in f1ff93b66844493a7b03101c7df66ac958c62418..c02e0e7754a76886e55b976a3a4fac20100cd35d
2019-02-26 13:37:28 -0500 to 2019-03-25 16:52:56 -0400
- dropck: The drop order is now defined (rust-lang-nursery/nomicon#113)

## reference

3 commits in 27ad493a10364e907ec476e2ad61e8a1614b57e1..98f90ff4de8e588f651f0fb493b5c7496551cd59
2019-03-26 02:06:15 +0100 to 2019-04-06 09:29:08 -0700
- Document repr packed(N). (rust-lang-nursery/reference#553)
- Fix broken link in glossary. (rust-lang-nursery/reference#558)
- Typo fixes (rust-lang-nursery/reference#556)

## embedded-book

2 commits in 07fd3880ea0874d82b1d9ed30ad3427ec98b4e8a..7989c723607ef5b13b57208022259e6c771e11d0
2019-03-27 15:40:52 +0000 to 2019-04-04 12:14:37 +0000
- fix rust-embedded/book#182  (rust-embedded/book#183)
- Add openocd to list of installable packages  (rust-embedded/book#179)

3 files changed, 0 insertions, 0 deletions

diff --git a/src/doc/embedded-book b/src/doc/embedded-book
-Subproject 07fd3880ea0874d82b1d9ed30ad3427ec98b4e8
+Subproject 7989c723607ef5b13b57208022259e6c771e11d
diff --git a/src/doc/nomicon b/src/doc/nomicon
-Subproject f1ff93b66844493a7b03101c7df66ac958c6241
+Subproject c02e0e7754a76886e55b976a3a4fac20100cd35
diff --git a/src/doc/reference b/src/doc/reference
-Subproject 27ad493a10364e907ec476e2ad61e8a1614b57e
+Subproject 98f90ff4de8e588f651f0fb493b5c7496551cd5