Register interrupt handlers once the APIC initialization is done

xtoskrnl/includes/ke.h

@@ -77,6 +77,11 @@ KeSetEvent(IN PKEVENT Event,
            IN KPRIORITY Increment,
            IN BOOLEAN Wait);
 
+XTAPI
+VOID
+KeSetInterruptHandler(IN ULONG Vector,
+                      IN PVOID Handler);
+
 XTAPI
 VOID
 KeStartThread(IN PKTHREAD Thread);