Fix IDT error # bug, add debug helper, continue debugging spawn_thread crash

The crash occurs after the newly-created stack is accessed, suggesting
that there is some bug in the paging code.
diff --git a/include/kernel/task.h b/include/kernel/task.h
index 38ff7ee..3126180 100644
--- a/include/kernel/task.h
+++ b/include/kernel/task.h
@@ -23,6 +23,7 @@
 	// NOTE: must be PAGE ALIGNED
 	uint last_stack_pos;
 };
+
 /**
  * The smallest schedulable unit, a thread of a process.
  */