devPrivates rework: hook up new mechanism in backwards-compatibility mode

on existing structures that support devPrivates.

include/privates.h

@@ -30,6 +30,13 @@ typedef struct _Private {
     struct _Private	*next;
 } PrivateRec;
 
+/*
+ * Backwards compatibility macro.  Use to get the proper PrivateRec
+ * reference from any of the structure types that supported the old
+ * devPrivates mechanism.
+ */
+#define DEVPRIV_PTR(foo) ((PrivateRec **)(&(foo)->devPrivates[0].ptr))
+
 /*
  * Request pre-allocated private space for your driver/module.
  * A non-null pScreen argument restricts to objects on a given screen.
@@ -156,4 +163,7 @@ dixLookupPrivateOffset(RESTYPE type);
 extern int
 dixRegisterPrivateOffset(RESTYPE type, unsigned offset);
 
+/* Used by the legacy support, don't rely on this being here */
+#define PadToLong(w) ((((w) + sizeof(long)-1) / sizeof(long)) * sizeof(long))
+
 #endif /* PRIVATES_H */