Add DARWIN_USE_64BIT_INODE on OSX to match stat.h

On MacOSX when DARWIN_USE_64BIT_INODE is specified ino_t is ulong and the
stat structure members are switched around.
Merge pull request #828 from dsp/ino64_t-support

Add DARWIN_USE_64BIT_INODE on OSX to match stat.h