LibC: Add dummy signal.h

libc/include/signal.h

@@ -0,0 +1,12 @@
+#pragma onces
+
+#include <sys/cdefs.h>
+
+__BEGIN_DECLS
+
+typedef int sig_atomic_t;
+
+int		raise(int);
+void	(*signal(int, void (*)(int)))(int);
+
+__END_DECLS