Prevent pre-emption during install_irq_handler

src/kernel/arch_i386/interrupts.c

@@ -126,8 +126,10 @@ void kernel_panic(char *message, cpu_registers_t *regs){
 }
 
 void install_irq_handler(void (*handler)(), uint8_t irqno){
+    asm("cli");
     interrupt_handlers[irqno] = handler;
     // printf("called\n");
+    asm("sti");
 }
 void *get_irq_handler(uint8_t irqno){
     return interrupt_handlers[irqno];