[core] fix state handling of self destruct

If a contract self destructs to self and then receives funds within the
same transaction, it is possible for its stale state to be saved. This
change removes that possibility by checking for deleted state objects
before returning them.

core/state/statedb.go

@@ -542,7 +542,10 @@ func (db *DB) createObject(addr common.Address) (newobj, prev *Object) {
 		db.journal.append(resetObjectChange{prev: prev})
 	}
 	db.setStateObject(newobj)
-	return newobj, prev
+	if prev != nil && !prev.deleted {
+		return newobj, prev
+	}
+	return newobj, nil
 }
 
 // CreateAccount explicitly creates a state object. If a state object with the address