fix: re-enable shareable read only executable logic

src/vm/page.c

@@ -183,7 +183,6 @@ page_load_file (struct page_entry *page)
      panics as this should not happen if eviction is working correctly. */
   struct thread *t = thread_current ();
   bool shareable = !page->writable && file_compare (page->file, t->exec_file);
-  shareable = false;
   if (shareable)
     {
       lock_acquire (&shared_file_pages_lock);