Initial reorg.

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

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

@@ -0,0 +1,53 @@
+use crate::fs::{FileType, Metadata};
+use std::{ffi, io};
+
+/// Entries returned by the ReadDir iterator.
+///
+/// This corresponds to [`std::fs::DirEntry`].
+///
+/// Unlike `std::fs::DirEntry`, this API has no `DirEntry::path`, because
+/// absolute paths don't interoperate well with the capability-oriented
+/// security model.  
+///
+/// TODO: Not yet implemented.
+///
+/// [`std::fs::DirEntry`]: https://doc.rust-lang.org/std/fs/struct.DirEntry.html
+pub struct DirEntry {}
+
+impl DirEntry {
+    /// Returns the metadata for the file that this entry points at.
+    ///
+    /// This corresponds to [`std::fs::DirEntry::metadata`].
+    ///
+    /// TODO: Not yet implemented.
+    ///
+    /// [`std::fs::DirEntry::metadata`]: https://doc.rust-lang.org/std/fs/struct.DirEntry.html#method.metadata
+    pub fn metadata(&self) -> io::Result<Metadata> {
+        unimplemented!("DirEntry::metadata");
+    }
+
+    /// Returns the file type for the file that this entry points at.
+    ///
+    /// This to [`std::fs::DirEntry::file_type`].
+    ///
+    /// TODO: Not yet implemented.
+    ///
+    /// [`std::fs::DirEntry::file_type`]: https://doc.rust-lang.org/std/fs/struct.DirEntry.html#method.file_type
+    pub fn file_type(&self) -> io::Result<FileType> {
+        unimplemented!("DirEntry::file_type");
+    }
+
+    /// Returns the bare file name of this directory entry without any other leading path component.
+    ///
+    /// This corresponds to [`std::fs::DirEntry::file_name`], though it returns
+    /// `String` rather than `OsString`.
+    ///
+    /// TODO: Not yet implemented.
+    ///
+    /// [`std::fs::DirEntry::file_name`]: https://doc.rust-lang.org/std/fs/struct.DirEntry.html#method.file_name
+    pub fn file_name(&self) -> String {
+        unimplemented!("DirEntry::file_name");
+    }
+}
+
+// TODO: impl Debug for DirEntry