Kernel: Add SMP message StackTrace

This event is sent when user presses ctrl+{F1-F12} and it will dump the
corresponding processor's stack trace. This is really helpful for
detecting deadlocks in the system

kernel/include/kernel/Processor.h

@@ -33,6 +33,7 @@ namespace Kernel
 				FlushTLB,
 				NewThread,
 				UnblockThread,
+				StackTrace,
 			};
 			SMPMessage* next { nullptr };
 			Type type;
@@ -45,6 +46,7 @@ namespace Kernel
 				} flush_tlb;
 				SchedulerQueue::Node* new_thread;
 				SchedulerQueue::Node* unblock_thread;
+				bool dummy;
 			};
 		};