Log Message:
rust: Update to 1.29.0.

Version 1.29.0 (2018-09-13)
==========================

Compiler
--------
- [Bumped minimum LLVM version to 5.0.][51899]
- [Added `powerpc64le-unknown-linux-musl` target.][51619]
- [Added `aarch64-unknown-hermit` and `x86_64-unknown-hermit` targets.][52861]

Libraries
---------
- [`Once::call_once` now no longer requires `Once` to be `'static`.][52239]
- [`BuildHasherDefault` now implements `PartialEq` and `Eq`.][52402]
- [`Box<CStr>`, `Box<OsStr>`, and `Box<Path>` now implement \ 
`Clone`.][51912]
- [Implemented `PartialEq<&str>` for `OsString` and \ 
`PartialEq<OsString>`
  for `&str`.][51178]
- [`Cell<T>` now allows `T` to be unsized.][50494]
- [`SocketAddr` is now stable on Redox.][52656]

Stabilized APIs
---------------
- [`Arc::downcast`]
- [`Iterator::flatten`]
- [`Rc::downcast`]

Cargo
-----
- [Cargo can silently fix some bad lockfiles ][cargo/5831] You can use
  `--locked` to disable this behaviour.
- [`cargo-install` will now allow you to cross compile an install
  using `--target`][cargo/5614]
- [Added the `cargo-fix` subcommand to automatically move project code from
  2015 edition to 2018.][cargo/5723]

Misc
----
- [`rustdoc` now has the `--cap-lints` option which demotes all lints above
  the specified level to that level.][52354] For example `--cap-lints warn`
  will demote `deny` and `forbid` lints to `warn`.
- [`rustc` and `rustdoc` will now have the exit code of `1` if compilation
  fails, and `101` if there is a panic.][52197]
- [A preview of clippy has been made available through rustup.][51122]
  You can install the preview with `rustup component add clippy-preview`

Compatibility Notes
-------------------
- [`str::{slice_unchecked, slice_unchecked_mut}` are now deprecated.][51807]
  Use `str::get_unchecked(begin..end)` instead.
- [`std::env::home_dir` is now deprecated for its unintuitive behaviour.][51656]
  Consider using the `home_dir` function from
  https://crates.io/crates/dirs instead.
- [`rustc` will no longer silently ignore invalid data in target spec.][52330]

[52861]: https://github.com/rust-lang/rust/pull/52861/
[52656]: https://github.com/rust-lang/rust/pull/52656/
[52239]: https://github.com/rust-lang/rust/pull/52239/
[52330]: https://github.com/rust-lang/rust/pull/52330/
[52354]: https://github.com/rust-lang/rust/pull/52354/
[52402]: https://github.com/rust-lang/rust/pull/52402/
[52103]: https://github.com/rust-lang/rust/pull/52103/
[52197]: https://github.com/rust-lang/rust/pull/52197/
[51807]: https://github.com/rust-lang/rust/pull/51807/
[51899]: https://github.com/rust-lang/rust/pull/51899/
[51912]: https://github.com/rust-lang/rust/pull/51912/
[51511]: https://github.com/rust-lang/rust/pull/51511/
[51619]: https://github.com/rust-lang/rust/pull/51619/
[51656]: https://github.com/rust-lang/rust/pull/51656/
[51178]: https://github.com/rust-lang/rust/pull/51178/
[51122]: https://github.com/rust-lang/rust/pull/51122
[50494]: https://github.com/rust-lang/rust/pull/50494/
[cargo/5614]: https://github.com/rust-lang/cargo/pull/5614/
[cargo/5723]: https://github.com/rust-lang/cargo/pull/5723/
[cargo/5831]: https://github.com/rust-lang/cargo/pull/5831/
[`Arc::downcast`]: https://doc.rust-lang.org/std/sync/struct.Arc.html#method.downcast
[`Iterator::flatten`]: \ 
https://doc.rust-lang.org/std/iter/trait.Iterator.html#method.flatten
[`Rc::downcast`]: https://doc.rust-lang.org/std/rc/struct.Rc.html#method.downcast