It's a bit odd to single out just android when we don't do this for any other cross compiling targets. Android builds will still work since we just pass the full path for gcc and ar with `-C linker` and `-C ar`.

I did add the flag to compiletest though so it can find gdb. Though, i'm pretty sure we don't run debuginfo tests on android anyways right now.

[breaking-change]

This module is a foundation on which many other algorithms are built. When hardware support is missing, stubs are provided in libcompiler-rt.a, so this should be available on all platforms.

Due to our excellent macro hygiene, this involves having a global path and a
hidden module in libcore itself.

Explain why it should not exist, and the plan of attack for removing it.

There's no need to include this specific flag just for android. We can
already deal with what it tries to solve by using -C linker=/path/to/cc
and -C ar=/path/to/ar. The Makefiles for rustc already set this up when
we're crosscompiling.

I did add the flag to compiletest though so it can find gdb. Though, I'm
pretty sure we don't run debuginfo tests on android anyways right now.

[breaking-change]

It was thought that these failures only happened on windows, turns out they
happen on any 32-bit machine.

cc #14064

Reader.read_at_least() ensures that at least a given number of bytes
have been read. The most common use-case for this is ensuring at least 1
byte has been read. If the reader returns 0 enough times in a row, a new
error kind NoProgress will be returned instead of looping infinitely.

This change is necessary in order to properly support Readers that
repeatedly return 0, either because they're broken, or because they're
attempting to do a non-blocking read on some resource that never becomes
available.

Also add .push() and .push_at_least() methods. push() is like read() but
the results are appended to the passed Vec.

Remove Reader.fill() and Reader.push_exact() as they end up being thin
wrappers around read_at_least() and push_at_least().

[breaking-change]

Reader.read_at_least() ensures that at least a given number of bytes
have been read. The most common use-case for this is ensuring at least 1
byte has been read. If the reader returns 0 enough times in a row, a new
error kind NoProgress will be returned instead of looping infinitely.

This change is necessary in order to properly support Readers that
repeatedly return 0, either because they're broken, or because they're
attempting to do a non-blocking read on some resource that never becomes
available.

Also add .push() and .push_at_least() methods. push() is like read() but
the results are appended to the passed Vec.

Remove Reader.fill() and Reader.push_exact() as they end up being thin
wrappers around read_at_least() and push_at_least().

[breaking-change]

Closes #14184 (std: Move the owned module from core to std)
Closes #14183 (Allow blocks in const expressions)
Closes #14176 (Add tests for from_bits.)
Closes #14175 (Replaced ~T by Box<T> in manual)
Closes #14173 (Implements Default trait for BigInt and BigUint)
Closes #14171 (Fix #8391)
Closes #14159 (Clean up unicode code in libstd)
Closes #14126 (docs: Add a not found page)
Closes #14123 (add a line to the example to clarify semantics)
Closes #14106 (Pretty printer improvements)
Closes #14083 (rustllvm: Add LLVMRustArrayType)
Closes #13957 (io: Implement process wait timeouts)

This implements set_timeout() for std::io::Process which will affect wait()
operations on the process. This follows the same pattern as the rest of the
timeouts emerging in std::io::net.

The implementation was super easy for everything except libnative on unix
(backwards from usual!), which required a good bit of signal handling. There's a
doc comment explaining the strategy in libnative. Internally, this also required
refactoring the "helper thread" implementation used by libnative to allow for an
extra helper thread (not just the timer).

This is a breaking change in terms of the io::Process API. It is now possible
for wait() to fail, and subsequently wait_with_output(). These two functions now
return IoResult<T> due to the fact that they can time out.

Additionally, the wait_with_output() function has moved from taking `&mut self`
to taking `self`. If a timeout occurs while waiting with output, the semantics
are undesirable in almost all cases if attempting to re-wait on the process.
Equivalent functionality can still be achieved by dealing with the output
handles manually.

[breaking-change]

cc #13523

LLVM internally uses `uint64_t` for array size, but the corresponding
C API (`LLVMArrayType`) uses `unsigned int` so ths value is truncated.
Therefore rustc generates wrong type for fixed-sized large vector e.g.
`[0 x i8]` for `[0u8, ..(1 << 32)]`.

This patch adds `LLVMRustArrayType` function for `uint64_t` support.

When printing doc comments, always put a newline after them in a macro
invocation to ensure that a line-doc-comment doesn't consume remaining tokens on
the line.

Now that the #[deriving] attribute is removed, the raw_pointers_deriving lint
was broken. This commit restores the lint by preserving lint attributes
across #[deriving] to the implementations and using #[automatically_derived] as
the trigger for activating the lint.

Previously, literals "1i" were printed as "1". This fixes the
numeric-method-autoexport test for pretty printing.

When expanding, an extra unsafe block is generated which is currently not
handled well.

The pretty printer handles inlines comments quite badly

This uses the trick of replacing the << token with a < token to parse closure
types correctly.

Closes #13324

Integers are always parsed as a u64 in libsyntax, but they're stored as i64. The
parser and pretty printer both printed an i64 instead of u64, sometimes
introducing an extra negative sign.

* Added `// no-pretty-expanded` to pretty-print a test, but not run it through
  the `expanded` variant.
* Removed #[deriving] and other expanded attributes after they are expanded
* Removed hacks around &str and &&str and friends (from both the parser and the
  pretty printer).
* Un-ignored a bunch of tests

After testing `--pretty normal`, it tries to run `--pretty expanded` and
typecheck output.
Here we don't check convergence since it really diverges: for every
iteration, some extra lines (e.g.`extern crate std`) are inserted.

Some tests are `ignore-pretty`-ed since they cause various issues
with `--pretty expanded`.

The tests use managed boxes, but are not perfectly feature-gated because
they use `@` inside macros. (It causes issue after `--pretty expanded`.)

Some `Expr` needs parentheses when printed. For example, without
parentheses, `ExprUnary(UnNeg, ExprBinary(BiAdd, ..))` becomes
`-lhs + rhs` which is wrong.

Those cases don't appear in ordinary code (since parentheses are
explicitly added) but they can appear in manually crafted ast by
extensions.

Inject `extern crate {std, native}` before `use` statements.
Add `#![feature(glob)]` since `use std::prelude::*` is used.

(Unfortunately `rustc --pretty expanded` does not converge,
since `extern crate` and `use std::prelude::*` is injected at every
iteration.)

This is to clarify that match construct doesn't define a new variable, since I
observed a person reading the Rust tutorial who seemed to incorrectly think
that it did. Fixes https://github.com/mozilla/rust/issues/13571 .

The Normalizations iterator has been renamed to Decompositions.
It does not currently include all forms of Unicode normalization,
but only encompasses decompositions.
If implemented recomposition would likely be a separate iterator
which works on the result of this one.

[breaking-change]

Closes #8391