Introduce <Xm/XmPrivate.h>

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

cde/include/Imakefile

@@ -1,7 +1,11 @@
 XCOMM $TOG: Imakefile /main/4 1997/07/09 10:03:24 samborn $
 #define PassCDebugFlags /**/
+#define IHaveSubdirs
 
 HEADERS = hpversion.h EUSCompat.h
+SUBDIRS = Xm
+
+MakeSubdirs($(SUBDIRS))
 
 all::