std: treat ENFILE as transient in the pidfd support probe

The probe handles EMFILE (per-process fd limit) as a transient error and re-probes later, but lets ENFILE (system-wide fd limit) fall through to the catch-all arm meant for an old kernel without pidfd support, which permanently caches the pidfd path as unsupported. ENFILE is the same transient condition, so handle both.

Author: valentynkit

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

@@ -510,7 +510,7 @@ impl Command {
                                     support = SPAWN;
                                 }
                             }
-                            Err(e) if e.raw_os_error() == Some(libc::EMFILE) => {
+                            Err(e) if matches!(e.raw_os_error(), Some(libc::EMFILE | libc::ENFILE)) => {
                                 // We're temporarily(?) out of file descriptors. In this case pidfd_spawnp would also fail
                                 // Don't update the support flag so we can probe again later.
                                 return Err(e)