test_bpf: extend tests for 32-bit endianness conversion

Currently "ALU_END_FROM_BE 32" and "ALU_END_FROM_LE 32" do not test if
the upper bits of the result are zeros (the arm64 JIT had such bugs).
Extend the two tests to catch this.
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@plumgrid.com>
Signed-off-by: NXi Wang <xi.wang@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

lib/test_bpf.c

@@ -3674,6 +3674,9 @@ static struct bpf_test tests[] = {
 		.u.insns_int = {
 			BPF_LD_IMM64(R0, 0x0123456789abcdefLL),
 			BPF_ENDIAN(BPF_FROM_BE, R0, 32),
+			BPF_ALU64_REG(BPF_MOV, R1, R0),
+			BPF_ALU64_IMM(BPF_RSH, R1, 32),
+			BPF_ALU32_REG(BPF_ADD, R0, R1), /* R1 = 0 */
 			BPF_EXIT_INSN(),
 		},
 		INTERNAL,
@@ -3708,6 +3711,9 @@ static struct bpf_test tests[] = {
 		.u.insns_int = {
 			BPF_LD_IMM64(R0, 0x0123456789abcdefLL),
 			BPF_ENDIAN(BPF_FROM_LE, R0, 32),
+			BPF_ALU64_REG(BPF_MOV, R1, R0),
+			BPF_ALU64_IMM(BPF_RSH, R1, 32),
+			BPF_ALU32_REG(BPF_ADD, R0, R1), /* R1 = 0 */
 			BPF_EXIT_INSN(),
 		},
 		INTERNAL,