Implement RtlWideStringConcatenate() routine

sdk/xtdk/rtlfuncs.h

@@ -73,6 +73,12 @@ RtlWideStringCompare(IN CONST PWCHAR String1,
                      IN CONST PWCHAR String2,
                      IN CONST ULONG Length);
 
+XTCDECL
+PWCHAR
+RtlWideStringConcatenate(PWCHAR Destination,
+                         PWCHAR Source,
+                         SIZE_T Count);
+
 XTCDECL
 SIZE_T
 RtlWideStringLength(IN CONST PWCHAR String,