Code to use `ty::substs` in trans. As part of this, uncovered (and fixed) issue #14050.

r? @pcwalton

`/data/local/tmp` seems to be more common.

This test runs successfully manually, but the bots are having trouble getting
this test to pass. Ignore it on freebsd for now.

This patch allows for using derivings for `kinds` in libcore

r? @alexcrichton 

fixing #13866

Attribute grammar in reference manual allowed `#[foo, bar]`, which does not match parser behavior.

Also rename nonterminals to match parser code.

Fix #13825.

ty::substs struct. This is a holdover from the olden days of yore. This patch
removes the last vestiges of that practice. This is part of the work
I was doing on #5527.

This was intended as part of the I/O timeouts commit, but it was mistakenly
forgotten. The type of the timeout argument is not guaranteed to remain constant
into the future.

I changed the documentation for the BigUint to reflection the deprecation of ~[T] in favor of Vec<T>.

Just small bits of polish.

With `~[T]` no longer growable, the `FromIterator` impl for `~[T]` doesn't make
much sense. Not only that, but nearly everywhere it is used is to convert from
a `Vec<T>` into a `~[T]`, for the sake of maintaining existing APIs. This turns
out to be a performance loss, as it means every API that returns `~[T]`, even a
supposedly non-copying one, is in fact doing extra allocations and memcpy's.
Even `&[T].to_owned()` is going through `Vec<T>` first.

Remove the `FromIterator` impl for `~[T]`, and adjust all the APIs that relied
on it to start using `Vec<T>` instead. This includes rewriting
`&[T].to_owned()` to be more efficient, among other performance wins.

Also add a new mechanism to go from `Vec<T>` -> `~[T]`, just in case anyone
truly needs that, using the new trait `FromVec`.

[breaking-change]

The code in resolve erroneously assumed that private enums weren't visited, so
the logic was adjusted to check to see if the enum definition itself was public.

Closes #11680

Is this what you had in mind?

Closes #11493

libstd: Check TMPDIR for android as well and if not set use '/data/local/tmp' instead of '/data/tmp'.

As part of #5527 I had to make some changes here and I just couldn't take it anymore. Refactor the writeback code. Should be functionally equivalent to the old stuff.

r? @pcwalton

fixing #13866

This code does not belong in libstd, and rather belongs in a dedicated crate. In
the future, the syntax::ext::format module should move to the fmt_macros crate
(hence the name of the crate), but for now the fmt_macros crate will only
contain the format string parser.

The entire fmt_macros crate is marked #[experimental] because it is not meant
for general consumption, only the format!() interface is officially supported,
not the internals.

This is a breaking change for anyone using the internals of std::fmt::parse.
Some of the flags have moved to std::fmt::rt, while the actual parsing support
has all moved to the fmt_macros library.

[breaking-change]

There was no reason to remove them from slice. They're testing methods
defined in slice, so that's where they belong.

Leave vec with copies of the partition/partitioned tests because it has
its own implementation of those methods.

Bring back the Decodable impl for ~[T], this time using FromVec. It's
still not recommended that anyone use this, but at least it's available
if necessary.

API Changes:

- &[T] and ~[T] no longer support the addition operator (+)

Add a new trait FromVec with one self-less method from_vec(). This is
kind of like FromIterator, but it consumes a Vec<T>. It's only
implemented for ~[T], but the idea is post-DST it can be implemented for
any Boxed<[T]>.

Tweak the tutorial's section on vectors and strings, to slightly clarify
the difference between fixed-size vectors, vectors, and slices.

os::args() no longer auto-borrows to &[~str].

API Changes:

- GetAddrInfoRequest::run() returns Result<Vec<..>, ..>
- Process::spawn() returns Result<(.., Vec<..>), ..>

API Changes:

- GetAddrInfoRequest::run() returns Result<Vec<..>, ..>
- Process::spawn() returns Result(.., Vec<..>), ..>

API Changes:

- from_base64() returns Result<Vec<u8>, FromBase64Error>
- from_hex() returns Result<Vec<u8>, FromHexError>
- json::List is a Vec<Json>
- Decodable is no longer implemented on ~[T] (but Encodable still is)
- DecoderHelpers::read_to_vec() returns a Result<Vec<T>, E>

Adding two vectors now results in a Vec<T> instead of a ~[T].

Implement Add on Vec<T>.

API Changes:

- get_host_addresses() returns IoResult<Vec<IpAddr>>
- Process.extra_io is Vec<Option<io::PipeStream>>

os::env(), os::args(), and related functions now use Vec<T> instead of
~[T].

API changes:

- UnsafeArc::newN() returns Vec<UnsafeArc<T>>

API changes:

- OwnedAsciiCast returns Vec<Ascii> instead of ~[Ascii]
- OwnedAsciiCast is implemented on Vec<u8>
- AsciiStr.to_lower/upper() returns Vec<Ascii>
- IntoBytes::into_bytes() returns Vec<u8>
- float_to_str_bytes_common() returns (Vec<u8>, bool)

- StrSlice.to_utf16() now returns a Vec<u8>.
- Other miscellaneous fallout in std::str.