selftests/bpf: Cover tail-call cgroup storage prog-array checks

selftests/bpf: Cover tail-call cgroup storage prog-array checks

Add tail-call selftests for prog-array ownership when cgroup storage
is in use. Verify that loading succeeds when callers and callees reuse
the owner's cgroup storage map, and that loading fails for a different
storage map and for the A(storage) -> B(no storage) -> C(storage)
bridge case addressed in the previous commit.

Also verify that a storage-less leaf program which cannot perform tail
calls itself is still allowed to join a storage-owned prog array, while
a storage-less tail-caller is rejected also at map update time.

  # LDLIBS=-static PKG_CONFIG='pkg-config --static' ./vmtest.sh -- ./test_progs -t tailcalls
  [...]
  #475/25  tailcalls/tailcall_freplace:OK
  #475/26  tailcalls/tailcall_bpf2bpf_freplace:OK
  #475/27  tailcalls/tailcall_failure:OK
  #475/28  tailcalls/reject_tail_call_spin_lock:OK
  #475/29  tailcalls/reject_tail_call_rcu_lock:OK
  #475/30  tailcalls/reject_tail_call_preempt_lock:OK
  #475/31  tailcalls/reject_tail_call_ref:OK
  #475/32  tailcalls/tailcall_sleepable:OK
  #475/33  tailcalls/tailcall_cgrp_storage:OK
  #475/34  tailcalls/tailcall_cgrp_storage_diff_storage:OK
  #475/35  tailcalls/tailcall_cgrp_storage_no_storage:OK
  #475/36  tailcalls/tailcall_cgrp_storage_no_storage_leaf:OK
  #475/37  tailcalls/tailcall_cgrp_storage_no_storage_bridge:OK
  #475     tailcalls:OK
  Summary: 1/37 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Lin Ma <malin89@huawei.com>
Signed-off-by: Rongzhen Cui <cuirongzhen@huawei.com>
Signed-off-by: Jingguo Tan <tanjingguo@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20260610105539.705887-2-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>