(NEW_FUNCTIONS): Add fcntl64.
* cygwin.din: Export fcntl64. Make fcntl being SIGFE.
* fcntl.cc (fcntl_worker): New function.
(fcntl64): New function.
(_fcntl): Call fcntl_worker. Convert 32 bit flock structure into
64 bit flock structure and vice versa.
* fhandler.cc (fhandler_base::lock): Change 2nd parameter to
struct __flock64 *.
* fhandler_disk_file.cc (fhandler_disk_file::lock): Ditto. Rework
to be 64 bit aware.
* fhandler.h: Accomodate above method argument changes.
* include/cygwin/types.h: Add struct __flock32 and __flock64.
Define struct flock according to setting of __CYGWIN_USE_BIG_TYPES__.
* include/cygwin/version.h: Bump API minor number.