CA-120439: Use Unix.LargeFile for 32-bit machines
CA-120439: Use Unix.LargeFile for 32-bit machines

Without this, calls to stat will fail for files larger than 4GB.

Signed-off-by: Si Beaumont <a0992b7f1f450b4c7716d34b81a2d6f0877ae11a@citrix.com>

thomassa/vhd-tool,djs55/vhd-tool,euanh/vhd-tool,euanh/vhd-tool,simonjbeaumont/vhd-tool,djs55/vhd-tool