rust-lang/rust

* Update bootstrap compiler
* Update version to 1.33.0
* Remove some `#[cfg(stage0)]` annotations

Actually updating the version number is blocked on updating Cargo

Ever since we added a Cargo-based build system for the compiler the
standard library has always been a little special, it's never been able
to depend on crates.io crates for runtime dependencies. This has been a
result of various limitations, namely that Cargo doesn't understand that
crates from crates.io depend on libcore, so Cargo tries to build crates
before libcore is finished.

I had an idea this afternoon, however, which lifts the strategy
from #52919 to directly depend on crates.io crates from the standard
library. After all is said and done this removes a whopping three
submodules that we need to manage!

The basic idea here is that for any crate `std` depends on it adds an
*optional* dependency on an empty crate on crates.io, in this case named
`rustc-std-workspace-core`. This crate is overridden via `[patch]` in
this repository to point to a local crate we write, and *that* has a
`path` dependency on libcore.

Note that all `no_std` crates also depend on `compiler_builtins`, but if
we're not using submodules we can publish `compiler_builtins` to
crates.io and all crates can depend on it anyway! The basic strategy
then looks like:

* The standard library (or some transitive dep) decides to depend on a
  crate `foo`.
* The standard library adds

  ```toml
  [dependencies]
  foo = { version = "0.1", features = ['rustc-dep-of-std'] }
  ```
* The crate `foo` has an optional dependency on `rustc-std-workspace-core`
* The crate `foo` has an optional dependency on `compiler_builtins`
* The crate `foo` has a feature `rustc-dep-of-std` which activates these
  crates and any other necessary infrastructure in the crate.

A sample commit for `dlmalloc` [turns out to be quite simple][commit].
After that all `no_std` crates should largely build "as is" and still be
publishable on crates.io! Notably they should be able to continue to use
stable Rust if necessary, since the `rename-dependency` feature of Cargo
is soon stabilizing.

As a proof of concept, this commit removes the `dlmalloc`,
`libcompiler_builtins`, and `libc` submodules from this repository. Long
thorns in our side these are now gone for good and we can directly
depend on crates.io! It's hoped that in the long term we can bring in
other crates as necessary, but for now this is largely intended to
simply make it easier to manage these crates and remove submodules.

This should be a transparent non-breaking change for all users, but one
possible stickler is that this almost for sure breaks out-of-tree
`std`-building tools like `xargo` and `cargo-xbuild`. I think it should
be relatively easy to get them working, however, as all that's needed is
an entry in the `[patch]` section used to build the standard library.
Hopefully we can work with these tools to solve this problem!

[commit]: alexcrichton/dlmalloc-rs@28ee12d

* Also update the bootstrap compiler
* Update cargo to 1.32.0
* Clean out stage0 annotations

beta was switched to bootstrap from stable 1.29.2 since 1.29.2 got the aliasing bug workaround.
For extra sanity we should probably bootstrap from a beta that was built with these fixed appied in the host compiler.

Fixes bootstrap on AArch64

…lacrum"

This reverts commit fff1aba, reversing
changes made to 01172a7.

Holy cow that's a lot of `cfg(stage0)` removed and a lot of new stable language
features!

Fixes #42681

* Bump the release version to 1.25
* Bump the bootstrap compiler to the recent beta
* Allow using unstable rustdoc features on beta - this fix has been applied to
  the beta branch but needed to go to the master branch as well.

Also remove a number of `stage0` annotations and such

This commit updates the bootstrap compiler, bumps the version to 1.23, updates
Cargo, updates books, and updates crates.io dependencies

This commit updates the bootstrap compiler and clears out a number
of #[cfg(stage0)] annotations and related business

This commit bumps the master branch's version to 1.21.0 and also updates the
bootstrap compiler from the freshly minted beta release.

We've got a freshly minted beta compiler, let's update to use that on nightly!
This has a few other changes associated with it as well

* A bump to the rustc version number (to 1.19.0)
* Movement of the `cargo` and `rls` submodules to their "proper" location in
  `src/tools/{cargo,rls}`. Now that Cargo workspaces support the `exclude`
  option this can work.
* Updates of the `cargo` and `rls` submodules to their master branches.
* Tweak to the `src/stage0.txt` format to be more amenable for Cargo version
  numbers. On the beta channel Cargo will bootstrap from a different version
  than rustc (e.g. the version numbers are different), so we need different
  configuration for this.
* Addition of `dev` as a readable key in the `src/stage0.txt` format. If present
  then stage0 compilers are downloaded from `dev-static.rust-lang.org` instead
  of `static.rust-lang.org`. This is added to accomodate our updated release
  process with Travis and AppVeyor.

There was a serious ARM codegen bug in LLVM that was fixed by #40779,
also backported to beta.  This updates stage0 to 1.17.0-beta.3 to pick
up that change, so ARM can bootstrap natively again.

Fixes #41291
cc @arielb1

Now that we've also updated cargo's release process this commit also changes the
download location of Cargo from Cargos archives back to the static.r-l.o
archives. This should ensure that the Cargo download is the exact Cargo paired
with the rustc that we release.

The original motivation for hard links was to speed up the various stages of
rustbuild, but in the end this is causing problems on Windows (#39504).

This commit tweaks the build system to use copies instead of hard links
unconditionally to ensure that the files accessed by Windows are always
disjoint.

Locally this added .3s to a noop build, so it shouldn't be too much of a
regression hopefully!

This commit updates the version number to 1.17.0 as we're not on that version of
the nightly compiler, and at the same time this updates src/stage0.txt to
bootstrap from freshly minted beta compiler and beta Cargo.

I updated the beta compiler used to bootstrap the master branch in #38438 with
the intention of fixing Travis OSX linkage issues but I mistakenly forgot that
the PR only updated rustc, not Cargo itself. Cargo has a new release process
with downloads in a different location, so this commit updates rustbuild to
download from this new location by tracking revisions instead of Cargo nightly
dates.

stage0.txt: typo fix

The current beta that rustc is bootstrapping from contains a bug in Cargo that
erroneously links to OpenSSL in /usr/local, but this is fixed in the most recent
1.14 beta, so let's use that.

Now that we've got a beta build, let's use it!