bug#13316

  ndb alter table with big dicttabinfo
  send alter_tab_req fragmented as signal can get larger than MAX_MESSAGE_SIZE


ndb/src/kernel/blocks/dbdict/Dbdict.cpp:
  DictTabInfo used during alter table can easily becom larger than MAX_MESSAGE_SIZE
    send fragmented instead

ndb/src/kernel/blocks/dbdict/Dbdict.cpp

@@ -3036,7 +3036,7 @@ Dbdict::alterTable_backup_mutex_locked(Signal* signal,
   lreq->gci = tablePtr.p->gciTableCreated;
   lreq->requestType = AlterTabReq::AlterTablePrepare;
   
-  sendSignal(rg, GSN_ALTER_TAB_REQ, signal, 
+  sendFragmentedSignal(rg, GSN_ALTER_TAB_REQ, signal, 
 		       AlterTabReq::SignalLength, JBB);
 }
 
@@ -3521,7 +3521,7 @@ Dbdict::execALTER_TAB_CONF(Signal * signal){
 	lreq->gci = gci;
 	lreq->requestType = AlterTabReq::AlterTableCommit;
 	
-	sendSignal(rg, GSN_ALTER_TAB_REQ, signal, 
+	sendFragmentedSignal(rg, GSN_ALTER_TAB_REQ, signal, 
 			     AlterTabReq::SignalLength, JBB);
       }
     }