Interrupts: ensure is_in_handler is true if we know we are in a handler

kernel/include/interrupts/Interrupts.h

@@ -7,5 +7,6 @@ namespace Interrupts
     void disable();
 
     bool is_in_handler();
+    void ensure_handler();
     void return_from_handler(Context* context);
 }

kernel/src/interrupts/Interrupts.cpp

@@ -16,6 +16,11 @@ bool Interrupts::is_in_handler()
     return __is_in_interrupt_handler;
 }
 
+void Interrupts::ensure_handler()
+{
+    __is_in_interrupt_handler = true;
+}
+
 void Interrupts::return_from_handler(Context* context)
 {
     asm volatile("mov %0, %%rsp\n"