Take advantage of the new registers saved in the STACK16FRAME to turn
some 'register' functions into normal functions.
Removed the few remaining 'return' functions to simplify relay
handling.

diff --git a/misc/toolhelp.c b/misc/toolhelp.c
index d9a88b8..c480224 100644
--- a/misc/toolhelp.c
+++ b/misc/toolhelp.c
@@ -97,6 +97,16 @@
     return TRUE;
 }
 
+BOOL16 WINAPI InterruptRegister16( HTASK16 task, FARPROC callback )
+{
+    return TRUE;
+}
+
+BOOL16 WINAPI InterruptUnRegister16( HTASK16 task )
+{
+    return TRUE;
+}
+
 /***********************************************************************
  *           ToolHelpHook                             (KERNEL.341)
  *	see "Undocumented Windows"