HADD pin index fix

src/kyupy/techlib.py

@@ -34,6 +34,7 @@ class TechLib:
             if pin == 'B': return int(kind[3])
             if pin[0] == 'B': return int(pin[1]) - 1 + int(kind[3])
         for prefix, pins, index in [('HADD', ('B0', 'SO'), 1),
+                                    ('HADD', ('A0', 'C1'), 0),
                                     ('MUX21', ('S', 'S0'), 2),
                                     ('MX2', ('S0',), 2),
                                     ('TBUF', ('OE',), 1),