Avoid EOVERFLOW from stat() calls due to overflowing inode numbers. The btrfs filesystem now uses 64-bit inode numbers even on 32-bit systems. This can lead to spurious stat() failures, where EOVERFLOW is returned because the inode number does not fit into the 32-bit stat structure, even when the caller is not interested in the inode number. This patch builds with _FILE_OFFSET_BITS == 64 when possible, and deals with integers that may be too large to fit into a Lisp fixnum. For more information, see xemacs-patches message <CAHCOHQk_mPM6WgFChBsGafqhuazep6VED7swFoqfFXOV1r8org@mail.gmail.com>.