test: Add a test for fixed issue #11844

Closes #11844
rustc: Avoid out of bounds in check_match

Closes #12116
auto merge of #14293 : alexcrichton/rust/weak-lang-items, r=brson

This commit is part of the ongoing libstd facade efforts (cc #13851). The
compiler now recognizes some language items as "extern { fn foo(...); }" and
will automatically perform the following actions:

1. The foreign function has a pre-defined name.
2. The crate and downstream crates can only be built as rlibs until a crate
   defines the lang item itself.
3. The actual lang item has a pre-defined name.

This is essentially nicer compiler support for the hokey
core-depends-on-std-failure scheme today, but it is implemented the same way.
The details are a little more hidden under the covers.

In addition to failure, this commit promotes the eh_personality and
rust_stack_exhausted functions to official lang items. The compiler can generate
calls to these functions, causing linkage errors if they are left undefined. The
checking for these items is not as precise as it could be. Crates compiling with
`-Z no-landing-pads` will not need the eh_personality lang item, and crates
compiling with no split stacks won't need the stack exhausted lang item. For
ease, however, these items are checked for presence in all final outputs of the
compiler.

It is quite easy to define dummy versions of the functions necessary:

    #[lang = "stack_exhausted"]
    extern fn stack_exhausted() { /* ... */ }

    #[lang = "eh_personality"]
    extern fn eh_personality() { /* ... */ }

cc #11922, rust_stack_exhausted is now a lang item
cc #13851, libcollections is blocked on eh_personality becoming weak
rustc: Avoid an unwrap() in check_match

Closes #12369
test: Add a test for fixed issue #12567

Closes #12567
test: Add test for fixed issue #12796

Doesn't close #12796 because the error message is awful.
Change std inject attributes to outer attributes

The #[phase(syntax,link)] attribute on `extern crate std` needs to be an
outer attribute so it can pretty-print properly.

Also add `#![no_std]` and `#[feature(phase)]` so compiling the
pretty-printed source will work.
core: Stabilize the mem module

Excluding the functions inherited from the cast module last week (with marked
stability levels), these functions received the following treatment.

* size_of - this method has become #[stable]
* nonzero_size_of/nonzero_size_of_val - these methods have been removed
* min_align_of - this method is now #[stable]
* pref_align_of - this method has been renamed without the
  `pref_` prefix, and it is the "default alignment" now. This decision is in line
  with what clang does (see url linked in comment on function). This function
  is now #[stable].
* init - renamed to zeroed and marked #[stable]
* uninit - marked #[stable]
* move_val_init - renamed to overwrite and marked #[stable]
* {from,to}_{be,le}{16,32,64} - all functions marked #[stable]
* swap/replace/drop - marked #[stable]
* size_of_val/min_align_of_val/align_of_val - these functions are marked
  #[unstable], but will continue to exist in some form. Concerns have been
  raised about their `_val` prefix.

[breaking-change]
auto merge of #14259 : alexcrichton/rust/core-mem, r=brson

Excluding the functions inherited from the cast module last week (with marked
stability levels), these functions received the following treatment.

* size_of - this method has become #[stable]
* nonzero_size_of/nonzero_size_of_val - these methods have been removed
* min_align_of - this method is now #[stable]
* pref_align_of - this method has been renamed without the
  `pref_` prefix, and it is the "default alignment" now. This decision is in line
  with what clang does (see url linked in comment on function). This function
  is now #[stable].
* init - renamed to zeroed and marked #[stable]
* uninit - marked #[stable]
* move_val_init - renamed to overwrite and marked #[stable]
* {from,to}_{be,le}{16,32,64} - all functions marked #[stable]
* swap/replace/drop - marked #[stable]
* size_of_val/min_align_of_val/align_of_val - these functions are marked
  #[unstable], but will continue to exist in some form. Concerns have been
  raised about their `_val` prefix.
auto merge of #14315 : kballard/rust/stdreader_isatty, r=alexcrichton

StdWriter has .isatty(). StdReader can trivially vend the same function,
and someone asked today on IRC how to call isatty() on stdin.
auto merge of #14316 : kballard/rust/range_inclusive_no_toprimitive, r=alexcrichton
Updated doc with correct type.
auto merge of #14319 : kballard/rust/rename_rng_choose_option, r=alexcrichton

Rng.choose() is used so rarely that it doesn't necessitate having two
methods, especially since the failing, non-option variant also requires
Clone.

[breaking-change]
rustc: rename the lint `level` enum for style.

CamelCase all the way!
rustc: ng -> gn, fix a typo in a string.
rustc: improve error messages from wrong --pretty flowgraph use.

This defers to .fatal and .span_fatal for errors (rather than `fail!`
which prints the ICE message). It also adds the span lookup when an id
doesn't correspond to a block, to show what it is pointing at.

It also makes the argument parser slightly looser, so that passing
`--pretty flowgraph` recognises the `flowgraph` part and suggests to use
an integer.
auto merge of #14324 : zecozephyr/rust/docfix, r=luqmana
Remove two outdated FIXMEs from complex.rs
auto merge of #14326 : huonw/rust/tiny-fixes, r=pnkfelix

The changes to flowgraph make invalid invocations slightly more forgiving by (trying to) provide slightly more information and by avoiding the ICE message.
std: Change hash to reexport its own Writer

One of the long-term goals of the libstd facade is to move the collections
library underneath the standard library. This would imply that libcollections
today would invert its dependency with libstd.

One of the primary blockers for doing this is the HashMap collection. Of its two
major dependencies, hashing and randomness, this commit is the first step in
dealing with hashing.

When moving the hash module beneath libstd, it must break its primary dependence
on the io::Writer trait (used as the hashing state). The proposed strategy for
breaking this dependence is taking a similar path as core::fmt, which is to have
the hash module define its own "writer trait". This trait would be similar to
std::io::Writer, except that it would not return errors and it would have fewer
convenience methods.

The Hash trait today has its type parameter behind a feature gate (default type
parameters), so this pending change will likely break no code which hasn't opted
in to the feature gate. The SipState struct will lose its implementation of
io::Writer, but it will regain similar methods for dealing with writing data.

This change specifically prepares for the hash migration by modifying
deriving(Hash) to use the std::hash::Writer bound instead of the std::io::Writer
bound. This bound is currently wired to std::io::Writer, but after a snapshot it
will have no need to be wired to the io writer trait.