Prettify syscalls

include/sys/syscall.h

@@ -0,0 +1,10 @@
+#pragma once
+
+#define SYSCALL_NR_FORK         57
+int sys_fork(void *ctx);
+
+#define SYSCALL_NR_EXIT         60
+__attribute__((noreturn)) void sys_exit(int status);
+
+#define SYSCALL_NR_DEBUG_TRACE  255
+void sys_debug_trace(const char *msg);