GCC 4.1 fixes.

GCC 4.1 fixes.
* cygheap.h (cygheap_user): Remove unneeded class names from function
declaration.
* fhandler.h (fhandler_base): Ditto.
(fhandler_dev_floppy): Ditto.
(fhandler_console): Ditto.
* wininfo.h (wininfo): Ditto.
* exceptions.cc (sigpacket::process): Avoid compiler errors about gotos and
initialization.
* fhandler_fifo.cc (fhandler_fifo::open): Ditto.
* fhandler_floppy.cc (fhandler_dev_floppy::ioctl): Ditto.
* fhandler_tty.cc (fhandler_tty_slave::ioctl): Ditto.
* mmap.cc (mmap64): Ditto.
* pipe.cc (fhandler_pipe::open): Ditto.
* spawn.cc (spawn_guts): Ditto.
* sec_helper.cc: Fix some comments.
(get_null_sd): Move file-scope static to only function where it is used.