selftests/bpf: Check if mark_chain_precision() follows scalar ids

Check __mark_chain_precision() log to verify that scalars with same
IDs are marked as precise. Use several scenarios to test that
precision marks are propagated through:
- registers of scalar type with the same ID within one state;
- registers of scalar type with the same ID cross several states;
- registers of scalar type  with the same ID cross several stack frames;
- stack slot of scalar type with the same ID;
- multiple scalar IDs are tracked independently.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230613153824.3324830-3-eddyz87@gmail.com

tools/testing/selftests/bpf/prog_tests/verifier.c

@@ -50,6 +50,7 @@
 #include "verifier_regalloc.skel.h"
 #include "verifier_ringbuf.skel.h"
 #include "verifier_runtime_jit.skel.h"
+#include "verifier_scalar_ids.skel.h"
 #include "verifier_search_pruning.skel.h"
 #include "verifier_sock.skel.h"
 #include "verifier_spill_fill.skel.h"
@@ -150,6 +151,7 @@ void test_verifier_ref_tracking(void)         { RUN(verifier_ref_tracking); }
 void test_verifier_regalloc(void)             { RUN(verifier_regalloc); }
 void test_verifier_ringbuf(void)              { RUN(verifier_ringbuf); }
 void test_verifier_runtime_jit(void)          { RUN(verifier_runtime_jit); }
+void test_verifier_scalar_ids(void)           { RUN(verifier_scalar_ids); }
 void test_verifier_search_pruning(void)       { RUN(verifier_search_pruning); }
 void test_verifier_sock(void)                 { RUN(verifier_sock); }
 void test_verifier_spill_fill(void)           { RUN(verifier_spill_fill); }