The major impetus for this pull request was to remove all usage of `~fn()` in `librustuv`. This construct is going away as a language feature, and additionally it imposes the requirement that all I/O operations have at least one allocation. This allocation has been seen to have a fairly high performance impact in profiles of I/O benchmarks.

I've migrated `librustuv` away from all usage of `~fn()`, and at the same time it no longer allocates on every I/O operation anywhere. The scheduler is now much more tightly integrated with all of the libuv bindings and most of the uv callbacks are specialized functions for a certain procedure. This is a step backwards in terms of making `librustuv` usable anywhere else, but I think that the performance gains are a big win here.

In just a simple benchmark of reading/writing 4k of 0s at a time between a tcp client/server in separate processes on the same system, I have witnessed the throughput increase from ~750MB/s to ~1200MB/s with this change applied.

I'm still in the process of testing this change, although all the major bugs (to my knowledge) have been fleshed out and removed. There are still a few spurious segfaults, and that's what I'm currently investigating. In the meantime, I wanted to put this up for review to get some eyes on it other than mine. I'll update this once I've got all the tests passing reliably again.

When a channel is destroyed, it may attempt scheduler operations which could
move a task off of it's I/O scheduler. This is obviously a bad interaction, and
some finesse is required to make it work (making destructors run at the right
time).

Closes #10375

At this time, also point the libuv submodule to the official repo instead of my
own off to the side.

cc #10246
Closes #10329

It appears that uv's support for interacting with a stdio stream as a tty when
it's actually a pipe is pretty problematic. To get around this, promote a check
to see if the stream is a tty to the top of the tty constructor, and bail out
quickly if it's not identified as a tty.

Closes #10237

In the ideal world, uv I/O could be canceled safely at any time. In reality,
however, we are unable to do this. Right now linked failure is fairly flaky as
implemented in the runtime, making it very difficult to test whether the linked
failure mechanisms inside of the uv bindings are ready for this kind of
interaction.

Right now, all constructors will execute in a task::unkillable block, and all
homing I/O operations will prevent linked failure in the duration of the homing
operation. What this means is that tasks which perform I/O are still susceptible
to linked failure, but the I/O operations themselves will never get interrupted.
Instead, the linked failure will be received at the edge of the I/O operation.

It turns out that the uv implementation would cause use-after-free if the idle
callback was used after the call to `close`, and additionally nothing would ever
really work that well if `start()` were called twice. To change this, the
`start` and `close` methods were removed in favor of specifying the callback at
creation, and allowing destruction to take care of closing the watcher.

cc #10308

This exposes the ability to change the modification and access times on a file.

Closes #10266

Closes #10297

This cleans up the merging of removing ~fn() and removing C++ wrappers to a
compile-able and progress-ready state

Using an raii wrapper means that there's no need for a '_self' variant and we
can greatly reduce the amount of 'self_'-named variables.

This adds an other ABI option which allows a custom selection over the target
architecture and OS. The only current candidate for this change is that kernel32
on win32 uses stdcall, but on win64 it uses the cdecl calling convention.
Otherwise everywhere else this is defined as using the Cdecl calling convention.

cc #10049
Closes #8774

This adds an other ABI option which allows a custom selection over the target
architecture and OS. The only current candidate for this change is that kernel32
on win32 uses stdcall, but on win64 it uses the cdecl calling convention.
Otherwise everywhere else this is defined as using the Cdecl calling convention.

cc #10049
Closes #8774

Fully support multiple lifetime parameters on types and elsewhere, removing special treatment for `'self`. I am submitting this a touch early in that I plan to push a new commit with more tests specifically targeting types with multiple lifetime parameters -- but the current code bootstraps and passes `make check`.

Fixes #4846

Make irrelevant changes to regions-mock-tcx to convince the pretty printer to emit the same thing twice in a row

and use opt_str instead of opt_val in rustpkg

Closes #9311

This bug was already fixed, just needed a test.

Closes #9569

This Fixes #10265 and paves the way for fixing #9543. It works by adding a 'package_id' attribute by default for library crates that don't specify it. This is necessary to use the 'extern mod foo = "bar"' form instead of 'extern mod foo(name="bar") (as per #9543), because the former adds a required package_id when trying to link with the bar crate. I added a simple test to ensure that the default package_id value is being generated, and also added an explicit package_id in the link attribute in all rust libs to avoid getting warnings about default package_id values when building rust. 

I'm not sure this is something you're interested in, but I was playing around the Any trait a bit and I wanted to try it as a key in a HashMap. To do that, TypeId needs to implement IterBytes.