Add lock-digest example from more-traces

tests/regression/46-apron2/58-lock-digest.c

@@ -0,0 +1,36 @@
+// PARAM: --set ana.activated[+] apron --set ana.relation.privatization mutex-meet
+// TODO: why does this work? even with earlyglobs
+#include <pthread.h>
+#include <goblint.h>
+
+int g, h;
+pthread_mutex_t a = PTHREAD_MUTEX_INITIALIZER;
+
+void *t2(void *arg) {
+  pthread_mutex_lock(&a);
+  __goblint_check(h <= g); // TODO: should be h < g?
+  pthread_mutex_unlock(&a);
+  return NULL;
+}
+
+void *t1(void *arg) {
+  pthread_t x;
+  pthread_create(&x, NULL, t2, NULL);
+
+  pthread_mutex_lock(&a);
+  h = 11; g = 12;
+  pthread_mutex_unlock(&a);
+
+  return NULL;
+}
+
+int main() {
+  pthread_mutex_lock(&a);
+  h = 9;
+  g = 10;
+  pthread_mutex_unlock(&a);
+
+  pthread_t x;
+  pthread_create(&x, NULL, t1, NULL);
+  return 0;
+}