Kernel: Track when a thread is in the middle of crashing

There are certain checks that we should skip if the system is crashing.
The system can avoid stack overflow during crash, or even triple
faulting while while handling issues that can causes recursive panics
or aborts.

Kernel/Panic.cpp

@@ -10,6 +10,7 @@
 #include <Kernel/IO.h>
 #include <Kernel/KSyms.h>
 #include <Kernel/Panic.h>
+#include <Kernel/Thread.h>
 
 namespace Kernel {
 
@@ -25,6 +26,11 @@ namespace Kernel {
 
 void __panic(const char* file, unsigned int line, const char* function)
 {
+    // Avoid lock ranking checks on crashing paths, just try to get some debugging messages out.
+    auto thread = Thread::current();
+    if (thread)
+        thread->set_crashing();
+
     critical_dmesgln("at {}:{} in {}", file, line, function);
     dump_backtrace(PrintToScreen::Yes);
     if (kernel_command_line().boot_mode() == BootMode::SelfTest)