Extract symbolic-thread-array-init from silver searcher

tests/regression/03-practical/48-symbolic-thread-array-init.c

@@ -0,0 +1,36 @@
+// Per-thread array pointers passed via argument but initialized before thread create.
+// Extracted from silver searcher.
+#include <stdlib.h>
+#include <pthread.h>
+#include <goblint.h>
+extern int __VERIFIER_nondet_int();
+
+void *thread(void *arg) {
+  int *p = arg;
+  int i = *p; // NORACE
+  return NULL;
+}
+
+int main() {
+  int threads_total = __VERIFIER_nondet_int();
+  __goblint_assume(threads_total >= 0);
+
+  pthread_t *tids = malloc(threads_total * sizeof(pthread_t));
+  int *is = malloc(threads_total * sizeof(int));
+
+  // create threads
+  for (int i = 0; i < threads_total; i++) {
+    is[i] = i; // NORACE
+    pthread_create(&tids[i], NULL, &thread, &is[i]); // may fail but doesn't matter
+  }
+
+  // join threads
+  for (int i = 0; i < threads_total; i++) {
+    pthread_join(tids[i], NULL);
+  }
+
+  free(tids);
+  free(is);
+
+  return 0;
+}