TODOs:
* File::reopen_with_fdflags is unimplemented, File::get_fdflags is lying - these are
  fcntl on unix, reopenfile / require reopening on windows.



# Linux

* path_link
    - need DirExt::hard_link that follows symlinks.
* path_rename_trailing_slashes
    - trailing slash behavior of files is wrong: trailing slashes are ignored,
      should cause an error.
* remove_directory_trailing_slashes
    - cap-std Dir::remove_dir gives EINVAL when trying to remove dir with
      trailing slash. otherwise, everything passes.

* fd_flags_set
    - set_fdflags is not implemented. test wanted to clear O_APPEND mode
* path_filestat
    - fdstat.fs_flags is not populated correctly - APPEND | SYNC aren't
      present because File::get_fdflags isnt implemented correctly


# Windows

* fd_readdir
    - DirEntry metadata ino panics on windows: https://github.com/bytecodealliance/cap-std/issues/142
* file_allocate
    - call to fd_allocate(10,10) reduces size from 100 to 20
* interesting_paths
    - on windows, opening `dir/nested/file/` (line 53) with a trailing slash
      gets you a NOENT instead of a NOTDIR errno.
* nofollow_errors
    - panic in my io::Error translation code: Unhandled kind: Other, caused by
      "symlink encountered"
* path_rename
    - permission denied on windows to rename a dir to an existing empty dir

* path_link
    - fails on the first dangling symlink, which is before the hard_link
      following symlinks issue linux hits.

## "Trailing slashes are a bonified boondoggle" - Dan

* path_rename_trailing_slashes
* path_symlink_trailing_slashes
* remove_directory_trailing_slashes
* unlink_file_trailing_slashes

## Same missing functionality as over in Linux:

* fd_flags_set
* path_filestat