Initial reorg.

This is largely the same as #305, but updated for the current tree.

crates/wasi-common/src/fs/mod.rs

@@ -0,0 +1,51 @@
+//! A very experimental module modeled providing a high-level and safe
+//! filesystem interface, modeled after `std::fs`, implemented on top of
+//! WASI functions.
+//!
+//! Most functions in this API are not yet implemented!
+//!
+//! This corresponds to [`std::fs`].
+//!
+//! Instead of [`std::fs`'s free functions] which operate on paths, this
+//! crate has methods on [`Dir`] which operate on paths which must be
+//! relative to and within the directory.
+//!
+//! Since all functions which expose raw file descriptors are `unsafe`,
+//! I/O handles in this API are unforgeable (unsafe code notwithstanding).
+//! This combined with WASI's lack of absolute paths provides a natural
+//! capability-oriented interface.
+//!
+//! [`std::fs`]: https://doc.rust-lang.org/std/fs/index.html
+//! [`std::fs`'s free functions]: https://doc.rust-lang.org/std/fs/index.html#functions
+//! [`DIR`]: struct.Dir.html
+
+// TODO: When more things are implemented, remove these.
+#![allow(
+    unused_imports,
+    unreachable_code,
+    unused_variables,
+    unused_mut,
+    unused_unsafe,
+    dead_code
+)]
+
+mod dir;
+mod dir_builder;
+mod dir_entry;
+mod error;
+mod file;
+mod file_type;
+mod metadata;
+mod open_options;
+mod permissions;
+mod readdir;
+
+pub use dir::*;
+pub use dir_builder::*;
+pub use dir_entry::*;
+pub use file::*;
+pub use file_type::*;
+pub use metadata::*;
+pub use open_options::*;
+pub use permissions::*;
+pub use readdir::*;