We need ANSI C prototypes of certain Motif
functions that are not published in the official
header files.
<Xm/XmPrivate.h> header file contains
the prototypes extracted from the Motif source.
To re-create <Xm/XmPrivate.h>:
1) Make sure you have sources of libXm
(lib/Xm directory of the Motif distribution)
accessible via imports/motif/lib/Xm
2) rm include/Xm/XmPrivate.h
3) make includes