Include comment indicating that this may be a HACK.

Author: Doug-Lyons

win32ss/gdi/ntgdi/gdiobj.c

@@ -481,8 +481,9 @@ ENTRY_ReferenceEntryByHandle(HGDIOBJ hobj, FLONG fl)
     PENTRY pentry;
     PTHREADINFO pti = PsGetCurrentThreadWin32Thread();
 
-    /* Allow a window that is moving or resizing to have access to all of its child
-       windows dc's even if the dc belongs to another process i.e. 3D Screensaver  */
+    /* HACK: This may be a hack but it fixes CORE-5601.
+     * Allow a window that is moving or resizing to have access to all of its child
+     * windows dc's even if the dc belongs to another process i.e. 3D Screensaver  */
     if (pti && pti->TIF_flags & TIF_MOVESIZETRACKING)
         fl = GDIOBJFLAG_IGNOREPID;