MQDXP_* (Conversion exit parameter structure)

See:

MQDXP_STRUC_ID "DXPb"
MQDXP_STRUC_ID_ARRAY 'D','X','P','b'
MQDXP_VERSION_1 1 X'00000001'
MQDXP_CURRENT_VERSION 1 X'00000001'