Broken symlinks are ignored

[rileysu]

running this code snippet prints nothing:

  for entry in glob::glob("src/test-link").unwrap() {
      println!("{:?}", entry);
  }

given that test-link is a broken symlink:

touch test-file
ln -s test-file test-link
rm test-file

This can possibly be fixed by changing fs::metadata(&next_path).is_ok() to (fs::metadata(&next_path).is_ok() || fs::symlink_metadata(&next_path).is_ok()) on this line:
https://github.com/rust-lang-nursery/glob/blob/337d417ee872dc04e8e6faff4b7379141933df59/src/lib.rs#L857