Defines starting with `a' in bsd/netccitt

• A bsd/netccitt/hdlc.h:170
• ABM bsd/netccitt/hdlc.h:139
• ADDRESS_A bsd/netccitt/hdlc.h:86
• ADDRESS_B bsd/netccitt/hdlc.h:87
• ADDRLN bsd/netccitt/pk.h:106