Rollup merge of rust-lang#96234 - goffrie:eloop, r=thomcc

remove_dir_all_recursive: treat ELOOP the same as ENOTDIR

On older Linux kernels (I tested on 4.4, corresponding to Ubuntu 16.04), opening a symlink using `O_DIRECTORY | O_NOFOLLOW` returns `ELOOP` instead of `ENOTDIR`. We should handle it the same, since a symlink is still not a directory and needs to be `unlink`ed.

Author: Dylan-DPC

library/std/src/sys/unix/fs.rs

@@ -1647,8 +1647,9 @@ mod remove_dir_impl {
     fn remove_dir_all_recursive(parent_fd: Option<RawFd>, path: &CStr) -> io::Result<()> {
         // try opening as directory
         let fd = match openat_nofollow_dironly(parent_fd, &path) {
-            Err(err) if err.raw_os_error() == Some(libc::ENOTDIR) => {
+            Err(err) if matches!(err.raw_os_error(), Some(libc::ENOTDIR | libc::ELOOP)) => {
                 // not a directory - don't traverse further
+                // (for symlinks, older Linux kernels may return ELOOP instead of ENOTDIR)
                 return match parent_fd {
                     // unlink...
                     Some(parent_fd) => {