IO.xs: OP_SIBLING is too new

and IO is living a double life, so we must #define it for older
perls.

diff --git a/dist/IO/IO.xs b/dist/IO/IO.xs
index 5e30795..c1b7e91 100644 (file)
--- a/dist/IO/IO.xs
+++ b/dist/IO/IO.xs
@@ -61,6 +61,10 @@ typedef FILE * OutputStream;
 #  define dVAR dNOOP
 #endif
 
+#ifndef OP_SIBLING
+#  define OP_SIBLING(o) (o)->op_sibling
+#endif
+
 static int not_here(const char *s) __attribute__noreturn__;
 static int
 not_here(const char *s)