selftests/bpf: Migrate from bpf_prog_test_run

bpf_prog_test_run is being deprecated in favor of the OPTS-based
bpf_prog_test_run_opts.
We end up unable to use CHECK in most cases, so replace usages with
ASSERT_* calls.

Signed-off-by: Delyan Kratunov <delyank@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220202235423.1097270-2-delyank@fb.com

selftests/bpf: Add skb_pkt_end test

Add a test that currently makes LLVM generate assembly code:

$ llvm-objdump -S skb_pkt_end.o
0000000000000000 <main_prog>:
; if (skb_shorter(skb, ETH_IPV4_TCP_SIZE))
0: 61 12 50 00 00 00 00 00 r2 = *(u32 *)(r1 + 80)
1: 61 14 4c 00 00 00 00 00 r4 = *(u32 *)(r1 + 76)
2: bf 43 00 00 00 00 00 00 r3 = r4
3: 07 03 00 00 36 00 00 00 r3 += 54
4: b7 01 00 00 00 00 00 00 r1 = 0
5: 2d 23 02 00 00 00 00 00 if r3 > r2 goto +2 <LBB0_2>
6: 07 04 00 00 0e 00 00 00 r4 += 14
; if (skb_shorter(skb, ETH_IPV4_TCP_SIZE))
7: bf 41 00 00 00 00 00 00 r1 = r4
0000000000000040 <LBB0_2>:
8: b4 00 00 00 ff ff ff ff w0 = -1
; if (!(ip = get_iphdr(skb)))
9: 2d 23 05 00 00 00 00 00 if r3 > r2 goto +5 <LBB0_6>
; proto = ip->protocol;
10: 71 12 09 00 00 00 00 00 r2 = *(u8 *)(r1 + 9)
; if (proto != IPPROTO_TCP)
11: 56 02 03 00 06 00 00 00 if w2 != 6 goto +3 <LBB0_6>
; if (tcp->dest != 0)
12: 69 12 16 00 00 00 00 00 r2 = *(u16 *)(r1 + 22)
13: 56 02 01 00 00 00 00 00 if w2 != 0 goto +1 <LBB0_6>
; return tcp->urg_ptr;
14: 69 10 26 00 00 00 00 00 r0 = *(u16 *)(r1 + 38)
0000000000000078 <LBB0_6>:
; }
15: 95 00 00 00 00 00 00 00 exit

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20201111031213.25109-3-alexei.starovoitov@gmail.com