Add IPV6_FREEBIND from Linux 4.15

[Joseph Myers]

[Proposed for once the release changes for 2.27, and the post-release 
changes opening master for development for 2.28, have been committed.]

This patch adds the IPV6_FREEBIND macro from Linux 4.15 to
sysdeps/unix/sysv/linux/bits/in.h.

Tested for x86_64.

2018-02-01  Joseph Myers  <joseph@codesourcery.com>

	* sysdeps/unix/sysv/linux/bits/in.h (IPV6_FREEBIND): New macro.

diff --git a/sysdeps/unix/sysv/linux/bits/in.h b/sysdeps/unix/sysv/linux/bits/in.h
index fb64f1b..2c86102 100644
--- a/sysdeps/unix/sysv/linux/bits/in.h
+++ b/sysdeps/unix/sysv/linux/bits/in.h
@@ -228,6 +228,7 @@ struct in_pktinfo
 #define IPV6_TRANSPARENT	75
 #define IPV6_UNICAST_IF		76
 #define IPV6_RECVFRAGSIZE	77
+#define IPV6_FREEBIND		78
 
 /* Obsolete synonyms for the above.  */
 #if !__USE_KERNEL_IPV6_DEFS

-- 
Joseph S. Myers
joseph@codesourcery.com