cnt_need_fixup_before accordingly.
(dtable::dup2): Ditto.
(dtable::fixup_before_fork): New method.
(dtable::fixup_before_exec): Ditto.
* dtable.h (class dtable): Add member `cnt_need_fixup_before'. Add
definition for methods `dec_need_fixup_before', `inc_need_fixup_before',
`need_fixup_before', `fixup_before_exec' and `fixup_before_fork'.
* fhandler.h (class fhandler_base): Slight rearrangements. Add
definitions for methods `fixup_before_fork_exec'.
(class fhandler_socket): Eliminate superfluous constructor.
Add member `prot_info_ptr'. Add destructor. Add definitions for
methods `dup', `fixup_before_fork_exec', `fixup_after_fork' and
`fixup_after_exec'.
* fork.cc (fork_parent): Care for file types which need a fixup
before fork. Start child in suspended state then.
* net.cc: New global variable `ws2_32_handle' and `wsadata'.
(fdsock): Check for Winsock version. Call `set_socket_inheritance'
only if Winsock version < 2.0. Care for `need_fixup' count in fdtab.
(cygwin_socket): Eliminate call to `set_socket_inheritance'.
(cygwin_accept): Ditto.
(cygwin_rcmd): Ditto.
(cygwin_rresvport): Ditto.
(cygwin_rexec): Ditto.
(socketpair): Ditto.
(fhandler_socket::fhandler_socket): Set `need_fork_fixup'. Allocate
space for the WSAPROTOCOL_INFOA struct used in fixup.
(fhandler_socket::~fhandler_socket): New destructor.
(fhandler_socket::fixup_before_fork_exec): New method.
(fhandler_socket::fixup_after_fork): Ditto.
(fhandler_socket::dup): Ditto.
(wsock_init): New static function.
(LoadDLLinitfunc (wsock32)): Rearranged.
(LoadDLLinitfunc (ws2_32)): New function.
(dummy_autoload): Add autoload statemants for `WSADuplicateSocketA'
and `WSASocketA'.
* spawn.cc (spawn_guts): Care for file types which need a fixup
before exec. Start child in suspended state then.