Merge commit 4a39d0890894 from llvm-project (by Mark Johnston):

  [libc++] Fix filesystem::remove_all() on FreeBSD (#79540)

  remove_all_impl() opens the target path with O_NOFOLLOW, which fails if
  the target is a symbolic link. On FreeBSD, rather than returning ELOOP,
  openat() returns EMLINK. This is unlikely to change for compatibility
  reasons, see https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=214633 .

  Thus, check for EMLINK as well.

Reported by:	markj
PR:		276632
MFC after:	3 days

contrib/llvm-project/libcxx/src/filesystem/operations.cpp

@@ -823,8 +823,9 @@ uintmax_t remove_all_impl(int parent_directory, const path& p, error_code& ec) {
 
   // If opening `p` failed because it wasn't a directory, remove it as
   // a normal file instead. Note that `openat()` can return either ENOTDIR
-  // or ELOOP depending on the exact reason of the failure.
-  if (ec == errc::not_a_directory || ec == errc::too_many_symbolic_link_levels) {
+  // or ELOOP depending on the exact reason of the failure. On FreeBSD it
+  // may return EMLINK instead of ELOOP, contradicting POSIX.
+  if (ec == errc::not_a_directory || ec == errc::too_many_symbolic_link_levels || ec == errc::too_many_links) {
     ec.clear();
     if (::unlinkat(parent_directory, p.c_str(), /* flags = */0) == -1) {
       ec = detail::capture_errno();