Update libxml to 2.7.7.

third_party/libxml/hash.c

 /*
  * hash.c: chained hash tables
  *
  * Reference: Your favorite introductory book on algorithms
  *
  * Copyright (C) 2000 Bjorn Reese and Daniel Veillard.
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
  * copyright notice and this permission notice appear in all copies.
@@ skipping 302 matching lines @@
                     if (iter->name3)
                         xmlFree(iter->name3);
                 }
                 iter->payload = NULL;
                 if (!inside_table)
                     xmlFree(iter);
                 nbElems--;
                 inside_table = 0;
                 iter = next;
             }
-            inside_table = 0;
         }
         xmlFree(table->table);
     }
     if (table->dict)
         xmlDictFree(table->dict);
     xmlFree(table);
 }
 
 /**
  * xmlHashAddEntry:
@@ skipping 747 matching lines @@
                 return(0);
             }
             prev = entry;
         }
         return(-1);
     }
 }
 
 #define bottom_hash
 #include "elfgcchack.h"