fix some demo IRQs

src/demo/night.stalker.a

@@ -16,7 +16,7 @@
          sta   $6017
          sta   $603F
          jsr   $800
-         +RESET_VECTOR $106
+         +RESET_AND_IRQ_VECTOR $100
          lda   #$92
          sta   $0D
          lda   #$72

src/demo/space.quarks.a

@@ -14,7 +14,7 @@
          lda   #$4C
          sta   $3EC9
          jsr   $3E65      ; decompress/set reset vector
-         +RESET_VECTOR $100
+         +RESET_AND_IRQ_VECTOR $100
          lda   #$EA
          sta   $1C38
          sta   $1C39

src/macros.a

@@ -351,6 +351,16 @@
          sta   $3F4
 }
 
+!macro   RESET_AND_IRQ_VECTOR .addr {
+         lda   #<.addr
+         sta   $3F2
+         sta   $3FE
+         lda   #>.addr
+         sta   $3F3
+         sta   $3FF
+         eor   #$A5
+         sta   $3F4
+}
 ; for games that clobber $100-$105, the prelaunch code constructs a new reset vector
 ; somewhere else and sets its
 !macro   NEW_RESET_VECTOR .addr {