Deprecate IN from IRIX for removal in 3.0.
diff --git a/Lib/plat-irix5/IN.py b/Lib/plat-irix5/IN.py
index 2d67892..8f58176 100755
--- a/Lib/plat-irix5/IN.py
+++ b/Lib/plat-irix5/IN.py
@@ -1,4 +1,7 @@
 # Generated by h2py from /usr/include/netinet/in.h
+from warnings import warnpy3k
+warnpy3k("the IN module has been removed in Python 3.0", stacklevel=2)
+del warnpy3k
 
 # Included from sys/endian.h
 LITTLE_ENDIAN = 1234