native: start with interrupts disabled

cpu/native/irq_cpu.c

@@ -45,7 +45,7 @@
 #define ENABLE_DEBUG (0)
 #include "debug.h"
 
-volatile int native_interrupts_enabled;
+volatile int native_interrupts_enabled = 0;
 volatile int _native_in_isr;
 volatile int _native_in_syscall;
 
@@ -466,7 +466,6 @@ void native_interrupt_init(void)
     VALGRIND_DEBUG("VALGRIND_STACK_REGISTER(%p, %p)\n",
                    (void *)__isr_stack, (void*)((int)__isr_stack + sizeof(__isr_stack)));
 
-    native_interrupts_enabled = 1;
     _native_sigpend = 0;
 
     for (int i = 0; i < 255; i++) {

cpu/native/startup.c

@@ -32,6 +32,7 @@
 
 #include "kernel_init.h"
 #include "cpu.h"
+#include "irq.h"
 
 #include "board_internal.h"
 #include "native_internal.h"
@@ -334,5 +335,6 @@ __attribute__((constructor)) static void startup(int argc, char **argv)
     board_init();
 
     puts("RIOT native hardware initialization complete.\n");
+    irq_enable();
     kernel_init();
 }