Fix <sys/epoll.h> and <sys/system_properties.h> to include proper C++ inclusion guards
diff --git a/libc/include/sys/system_properties.h b/libc/include/sys/system_properties.h
index 2eb00cd..4fdc944 100644
--- a/libc/include/sys/system_properties.h
+++ b/libc/include/sys/system_properties.h
@@ -29,6 +29,10 @@
#ifndef _INCLUDE_SYS_SYSTEM_PROPERTIES_H
#define _INCLUDE_SYS_SYSTEM_PROPERTIES_H
+#include <sys/cdefs.h>
+
+__BEGIN_DECLS
+
typedef struct prop_info prop_info;
#define PROP_NAME_MAX 32
@@ -76,4 +80,6 @@
*/
const prop_info *__system_property_find_nth(unsigned n);
+__END_DECLS
+
#endif