Add missing header.

GJDuck · GJDuck · commit c08b98f76191 · 2022-07-20T11:04:10.000+08:00
diff --git a/src/e9patch/e9misc.cpp b/src/e9patch/e9misc.cpp
@@ -16,6 +16,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <cerrno>
 #include <cstdlib>
 
 #include <sys/mman.h>
