include: add version_compare helper function

nx-X11/programs/Xserver/include/misc.h

@@ -81,6 +81,7 @@ extern unsigned long serverGeneration;
 #include <nx-X11/Xfuncproto.h>
 #include <nx-X11/Xmd.h>
 #include <nx-X11/X.h>
+#include <stdint.h>
 
 #ifndef _XTYPEDEF_POINTER
 /* Don't let Xdefs.h define 'pointer' */
@@ -237,6 +238,28 @@ pad_to_int32(const int bytes) {
     return (((bytes) + 3) & ~3);
 }
 
+/**
+ * Compare the two version numbers comprising of major.minor.
+ *
+ * @return A value less than 0 if a is less than b, 0 if a is equal to b,
+ * or a value greater than 0
+ */
+static inline int
+version_compare(uint32_t a_major, uint32_t a_minor,
+                uint32_t b_major, uint32_t b_minor)
+{
+    if (a_major > b_major)
+        return 1;
+    if (a_major < b_major)
+        return -1;
+    if (a_minor > b_minor)
+        return 1;
+    if (a_minor < b_minor)
+        return -1;
+
+    return 0;
+}
+
 /* some macros to help swap requests, replies, and events */
 
 #define LengthRestB(stuff) \