Libunwind sandbox no longer needs to join sandboxee's userns.
This cleans up a lot of special handling for the libunwind sandbox.
PiperOrigin-RevId: 503140778
Change-Id: I020ea3adda05ae6ff74137b668a5fa7509c138f8
Follow-up changes might be required to fully fix up the contrib sandboxes.
PiperOrigin-RevId: 482475998
Change-Id: Iff631eb838a024b2f047a1be61bb27e35a8ff2f4
This addresses a latency issue - chroot_fs_refs called inside pivot_root
in the kernel can take several milliseconds on machines with many threads
running.
This might not always reduce latency for custom forkservers, as additional
fork can be more costly than pivot_root.
PiperOrigin-RevId: 281306284
Change-Id: If503ac76a70e5438e94caf708d79cb0219c66def
