rework zig fmt to use less syscalls and open fds

 * `std.fs.Dir.Entry.Kind` is moved to `std.fs.File.Kind`
 * `std.fs.File.Stat` gains the `kind` field, so performing a stat() on
   a File now tells what kind of file it is. On Windows this only will
   distinguish between directories and files.
 * rework zig fmt logic so that in the case of opening a file and
   discovering it to be a directory, it closes the file descriptor
   before re-opening it with O_DIRECTORY, using fewer simultaneous open
   file descriptors when walking a directory tree.
 * rework zig fmt logic so that it pays attention to the kind of
   directory entries, and when it sees a sub-directory it attempts to
   open it as a directory rather than a file, reducing the number of
   open() syscalls when walking a directory tree.

0 files changed, 0 insertions, 0 deletions