Fix issues with merging, duplicate references and definition of VM

src/vm/mmap.c

@@ -126,21 +126,3 @@ mmap_cleanup (struct hash_elem *e, void *aux UNUSED)
   struct mmap_entry *mmap = hash_entry (e, struct mmap_entry, elem);
   mmap_unmap (mmap);
 }
-
-/* Updates the 'owner' thread's page table entry for virtual address 'upage'
-   to have a present bit of 0 and stores the specified swap slot value in the
-   entry for later retrieval from disk. */
-void
-page_set_swap (struct thread *owner, void *upage, size_t swap_slot)
-{
-
-}
-
-/* Given that the page with user address 'upage' owned by 'owner' is flagged
-   to be in the swap disk via the owner's page table, returns its stored
-   swap slot. Otherwise panics the kernel. */
-size_t
-page_get_swap (struct thread *owner, void *upage)
-{
-  return 0;
-}