Implement initialization of new threads to track donation information, w/ S

src/threads/thread.c

@@ -510,9 +510,13 @@ init_thread (struct thread *t, const char *name, int priority)
   t->status = THREAD_BLOCKED;
   strlcpy (t->name, name, sizeof t->name);
   t->stack = (uint8_t *) t + PGSIZE;
-  t->priority = priority;
+  t->base_priority = priority;
   t->magic = THREAD_MAGIC;
 
+  list_init (&t->donors_list);
+  t->priority = t->base_priority;
+  t->waiting_lock = NULL;
+
   old_level = intr_disable ();
   list_push_back (&all_list, &t->allelem);
   intr_set_level (old_level);