Fix resolver if_* namespace (bug 17717).

Resolver code, brought in by pthreads (at least), uses if_* interfaces
that weren't in POSIX before 2001, resulting in linknamespace
failures.  This patch changes those interfaces to be weak aliases of
__if_* and makes the resolver use __if_* directly.

Tested for x86_64 (testsuite, and that disassembly of installed shared
libraries is unchanged by this patch).

	[BZ #17717]
	* inet/if_index.c (if_nametoindex): Rename to __if_nametoindex and
	define as weak alias of __if_nametoindex.  Use libc_hidden_weak.
	(if_indextoname): Rename to __if_indextoname and define as weak
	alias of __if_indextoname.  Use libc_hidden_weak.
	(if_freenameindex): Rename to __if_freenameindex and define as
	weak alias of __if_freenameindex.
	(if_nameindex): Rename to __if_nameindex and define as weak alias
	of __if_nameindex.
	* sysdeps/mach/hurd/if_index.c (if_nametoindex): Rename to
	__if_nametoindex and define as weak alias of __if_nametoindex.
	Use libc_hidden_weak.
	(if_freenameindex): Rename to __if_freenameindex and define as
	weak alias of __if_freenameindex.
	(if_nameindex): Rename to __if_nameindex and define as weak alias
	of __if_nameindex.
	(if_indextoname): Rename to __if_indextoname and define as weak
	alias of __if_indextoname.  Use libc_hidden_weak.
	* sysdeps/unix/sysv/linux/if_index.c (if_nametoindex): Rename to
	__if_nametoindex and define as weak alias of __if_nametoindex.
	Use libc_hidden_weak.
	(if_freenameindex): Rename to __if_freenameindex and define as
	weak alias of __if_freenameindex.  Use libc_hidden_weak.
	(if_nameindex_netlink): Use __if_freenameindex instead of
	if_freenameindex.
	(if_nameindex): Rename to __if_nameindex and define as weak alias
	of __if_nameindex.  Use libc_hidden_weak.
	(if_indextoname): Rename to __if_indextoname and define as weak
	alias of __if_indextoname.  Use libc_hidden_weak.
	* include/net/if.h [!_ISOMAC] (__if_nametoindex): Declare and use
	libc_hidden_proto.
	[!_ISOMAC] (__if_freenameindex): Likewise.
	* resolv/res_init.c (__res_vinit): Use __if_nametoindex instead of
	if_nametoindex.
	* conform/Makefile (test-xfail-XPG4/grp.h/linknamespace): Remove
	variable.
	(test-xfail-XPG4/pwd.h/linknamespace): Likewise.
	(test-xfail-UNIX98/aio.h/linknamespace): Likewise.
	(test-xfail-UNIX98/grp.h/linknamespace): Likewise.
	(test-xfail-UNIX98/pthread.h/linknamespace): Likewise.
	(test-xfail-UNIX98/pwd.h/linknamespace): Likewise.
	(test-xfail-UNIX98/sched.h/linknamespace): Likewise.
	(test-xfail-UNIX98/time.h/linknamespace): Likewise.

1 files changed, 1 insertions, 1 deletions

diff --git a/NEWS b/NEWS
index 11121cacb0..443475980a 100644
--- a/NEWS
+++ b/NEWS
@@ -14,7 +14,7 @@ Version 2.21
   17363, 17370, 17371, 17411, 17460, 17475, 17485, 17501, 17506, 17508,
   17522, 17555, 17570, 17571, 17572, 17573, 17574, 17581, 17582, 17583,
   17584, 17585, 17589, 17594, 17601, 17608, 17616, 17625, 17630, 17633,
-  17634, 17647, 17653, 17657, 17664, 17665, 17668, 17682.
+  17634, 17647, 17653, 17657, 17664, 17665, 17668, 17682, 17717.
 
 * CVE-2104-7817 The wordexp function could ignore the WRDE_NOCMD flag
   under certain input conditions resulting in the execution of a shell for