static bool states_equal(struct bpf_verifier_env *env,
			 struct bpf_verifier_state *old,
			 struct bpf_verifier_state *cur,
			 bool exact)
static bool states_equal(struct bpf_verifier_env *env,
			 struct bpf_verifier_state *old,
			 struct bpf_verifier_state *cur,
			 enum exact_level exact)