Kernel: Replace raw asm functions with naked ones

Author: https://github.com/Hendiadyoin1
Commit: 9b7e48c6bd
Pull-request: https://github.com/SerenityOS/serenity/pull/8457

Kernel/Arch/x86/Processor.h

@@ -32,6 +32,11 @@ struct ProcessorMessageEntry;
 struct TrapFrame;
 class ProcessorInfo;
 
+// FIXME: Find a better place for these
+extern "C" void thread_context_first_enter(void);
+extern "C" void exit_kernel_thread(void);
+extern "C" void do_assume_context(Thread* thread, u32 flags);
+
 struct [[gnu::aligned(16)]] FPUState
 {
     u8 buffer[512];