-lws2_32.
* ser-tcp.c (<winsock2.h>): Include, for Windows.
(ETIMEDOUT): Define, for Windows.
(ioctl): Likewise.
(closesocket): Define, for POSIX.
(net_open): Adjust for differences in socket functions between
Windows and UNIX.
(net_close): Likweise.
(net_read_prim): New function.
(net_write_prim): Likewise.
(_initialize_ser_tcp): Initialize winsock. Fill in read_prim and
write_prim.
* ser-unix.h (ser_unix_readcchar): Remove.
(ser_unix_read_prim): Declare.
(ser_unix_write_prim): Likewise.
* ser-unix.c (generic_readchar): Move to ser-base.c.
(ser_unix_wait_for): Likewise.
(do_unix_readchar): Likewise.
(ser_unix_readchar): Likewise.
(_initialize_ser_hardwire): Initialize read_prim and write_prim.
(ser_unix_read_prim): New function.
(ser_unix_write_prim): Likewise.
* ser-base.h (generic_readchar): Declare.
(ser_base_readchar): Likewise.
* ser-base.c (<winsock2.h>): Include, for windows.
(fd_event): Use the read primitive specified by the serial
interface.
(ser_base_wait_for): Moved from ser-unix.c
(do_ser_base_read_char): Likewise.
(generic_readchar): Likewise.
(ser_base_readchar): Likewise.
(ser_base_write): Use the write primitive specified by the serial
interface.
* ser-pipe.c (_initialize_ser_pipe): Use ser_base_readchar, not
ser_unix_readchar. Initialize read_prim and write_prim.
* serial.c (struct serial_ops): Add read_prim and write_prim.
* configure: Regenerate.