so that if we have a function like:
f(...) : p(x) {
  ...
}

p(x) is true inside the body of f.

Closes #694.

so that it can be used in places that import ty.

This essentially starts the bootstrapping one step earlier by building
the stdlib from source using the stage0 compiler and then using that
stdlib to build the stage1 compiler. (Instead of starting by building
the stage1 compiler and then building a stdlib with it).

This means we should now be able to add features to the stdlib and use
them in the compiler without having to do a snapshot. (On the flip
side, this means that we now need to do a snapshot if we want to use a
new language feature in the stdlib, but that doesn't really seem too
burdensome (we already need to snapshot if we want to use a new
language feature in the compiler)).

This lets us un-XFAIL task-comm-10.rs.

We're trying to get closer to doing correct move semantics for channel
operations. This involves a lot of cleanup (such as removing the
unused sched parameter from rust_vec constructor) and making
circular_buffer kernel_owned.

Added tagging for memory allocations. This means we give a string tag
to everything we allocate. If we leak something and TRACK_ALLOCATIONS
is enabled, then it's much easier now to tell exactly what is leaking.

This reverts commit df90f57a.

We should probably do another pretty-printing pass soon.

Closes #622.

I'm not sure if this is because of changes to glue generation in the
last few days while I've been working on other things, or if it's a
side effect of the improvements I made to typechecking for anonymous
objects, or something else, but I guess I'll take it!

Closes issue #543.

multiple static crates to be used.

This is just until unwinding works. Adds a flag to the runtime to turn
the memory leak checks on task destruction into warnings instead of fatal
errors. I am so sorry.

Issue #428

Fixes the Windoze breakage, I hope.