Linux error numbers for Rust

This library defines an Error struct that represents error numbers returned from Linux system calls.

On Linux, error numbers are architecture-specific. The arch modules provide access to error numbers for all supported architectures, and the top-level module re-exports error numbers for the current target platform.

To depend on linux-errno from a Bazel workspace:

```python load("@bazeltools//tools/builddefs/repo:http.bzl", "http_archive")

httparchive( name = "rustposix_errno", sha256 = "74e8d0d36c1e6e8c64f0e837f6414c65cf02757a09bdcbf788c04581008f3308", urls = ["https://github.com/jmillikin/rust-posix-errno/releases/download/v1.0.0/posix-errno-v1.0.0.tar.xz"], )

httparchive( name = "rustlinux_errno", sha256 = "...", urls = ["https://github.com/jmillikin/rust-linux-errno/releases/download/v1.0.0/linux-errno-v1.0.0.tar.xz"], ) ```

To depend on linux-errno from a Cargo workspace:

[dependencies] linux-errno = { version = "1.0.0" }