This commit stabilizes the platform-specific `io` modules, specifically around
the traits having to do with the raw representation of each object on each
platform.
Specifically, the following material was stabilized:
* `AsRaw{Fd,Socket,Handle}`
* `RawFd` (renamed from `Fd`)
* `RawHandle` (renamed from `Handle`)
* `RawSocket` (renamed from `Socket`)
* `AsRaw{Fd,Socket,Handle}` implementations
* `std::os::{unix, windows}::io`
The following material was added as `#[unstable]`:
* `FromRaw{Fd,Socket,Handle}`
* Implementations for various primitives
There are a number of future improvements that are possible to make to this
module, but this should cover a good bit of functionality desired from these
modules for now. Some specific future additions may include:
* `IntoRawXXX` traits to consume the raw representation and cancel the
auto-destructor.
* `Fd`, `Socket`, and `Handle` abstractions that behave like Rust objects and
have nice methods for various syscalls.
At this time though, these are considered backwards-compatible extensions and
will not be stabilized at this time.
This commit is a breaking change due to the addition of `Raw` in from of the
type aliases in each of the platform-specific modules.
[breaking-change]