[CA-118809] Use 64 bit abi

Signed-off-by: Ben Chalmers <Ben.Chalmers@citrix.com>
Merge pull request #3 from benchalmers/upstream-ca-118809

[CA-118809] Use 64 bit abi
Approved By : owen.smith@citrix.com
Merge branch 'upstream' of github.com:OwenSmith/win-xenvbd into upstream