errno may not be a variable; users must include errno.h instead of

declaring it like `extern int errno'.

src/lib/gen/io.c

@@ -81,8 +81,6 @@ struct iop {
     int (*notify) ();
 };
 
-extern int errno;
-
 void
 io_init(void)
 {

src/lib/gen/io_mask.c

@@ -38,8 +38,6 @@
 #include "empio.h"
 #include "io_mask.h"
 
-extern int errno;
-
 struct io_mask *
 iom_create(int what)
 {