This moves the raw struct layout of closures, vectors, boxes, and strings into a
new `unstable::raw` module. This is meant to be a centralized location to find
information for the layout of these values.

As safe method, `repr`, is provided to convert a rust value to its raw
representation. Unsafe methods to convert back are not provided because they are
rarely used and too numerous to write an implementation for each (not much of a
common pattern).

First, clean up the uses of "None" and "Some" to always use consistent title case matching the variant names.

Add .chain_mut_ref() which is a missing method. A use case example for this method is extraction of an optional value from an Option\<Container\> value.

Hello,

I made a tiny change to `tidy.py` so that it uses a regexp to find `// NOTE` comments. I could not find an easy way to write an automated test for this but if this is needed and possible I'd be happy to write one.
Please note that it also removes extra empty lines that appear after each of these warnings (I believe that there were not wanted).

On the performance side, `make tidy` is now a bit slower (running it 10 times in a row takes 71s on my machine, 65s before) but I don't think that it is performance sensitive.

Thanks!

This is a cleanup pull request that does:

* removes `os::as_c_charp`
* moves `str::as_buf` and `str::as_c_str` into `StrSlice`
* converts some functions from `StrSlice::as_buf` to `StrSlice::as_c_str`
* renames `StrSlice::as_buf` to `StrSlice::as_imm_buf` (and adds `StrSlice::as_mut_buf` to match `vec.rs`.
* renames `UniqueStr::as_bytes_with_null_consume` to `UniqueStr::to_bytes`
* and other misc cleanups and minor optimizations

Just an minor cleanup.

f0f4dcc r=huonw
25e9c4c r=graydon
a87c2d1 r=brson
16f369d r=cmr
9f05cc8 r=bstrie
e858055 r=huonw
5d80938 r=thestinger
05d03e7 r=cmr
8f86fa3b r=thestinger

Simplify Rc<T>/RcMut<T> by using ~T when allocating a reference counted
box.

The code to build the transmute intrinsic currently makes the invalid
assumption that if the in-type is non-immediate, the out-type is
non-immediate as well. But this is wrong, for example when transmuting
[int, ..1] to int. So we need to handle this fourth case as well.

Fixes #7988

Closes #4982.

Added missing memory orderings for atomic types. https://github.com/mozilla/rust/issues/7422

...(they still don't work).

Closes #5844 

Some machinery for enabling #[bench] benchmarks in std and some examples showing how to write them.

This allows for control over the section placement of static, static
mut, and fn items.  One caveat is that if a static and a static mut are
placed in the same section, the static is declared first, and the static
mut is assigned to, the generated program crashes.  For example:

#[link_section=".boot"]
static foo : uint = 0xdeadbeef;

#[link_section=".boot"]
static mut bar : uint = 0xcafebabe;

Declaring bar first would mark .bootdata as writable, preventing the
crash when bar is written to.

This just redoes various parts of workcache to support context-cloning (eventually quite crudely, via ARCs), the absence of which was blocking rustpkg from being able to use it. Better versions of this are possible (notably removing the ARCs on everything except the database) but it ought to work well enough for now.

This eliminates a copy and fixes a FIXME.

These uses are assuming the strings are null terminated, so it
should be using `as_c_str` instead of `as_buf`