Revert "hurd: Fix abi-tag, following ba90e05"

	and revert the corresponding part of ba90e05 which was making the fix
	necessary.

	* abi-tags: Revert ae20c9a: rename back gnu into gnu-gnu.
	* configure.ac, configure: Revert ba90e05: modify gnu-* host_os back
	into gnu-gnu, and update comment to refer to abi-tags.

ChangeLog

@@ -1,3 +1,9 @@
+2015-02-11  Samuel Thibault  <samuel.thibault@ens-lyon.org>
+
+	* abi-tags: Revert ae20c9a: rename back gnu into gnu-gnu.
+	* configure.ac, configure: Revert ba90e05: modify gnu-* host_os back
+	into gnu-gnu, and update comment to refer to abi-tags.
+
 2015-02-11  Joseph Myers  <joseph@codesourcery.com>
 
 	[BZ #15467]

abi-tags

@@ -18,7 +18,7 @@
 
 .*-.*-linux.*		0	2.0.0	# earliest compatible kernel version
 
-.*-.*-gnu.*		1	0.0.0
+.*-.*-gnu-gnu.*		1	0.0.0
 
 .*-sun-solaris2.*	2	2.0.0	# just an arbitrary value
 

configure

@@ -3742,6 +3742,18 @@ if test "$build_pt_chown" = yes; then
 
 fi
 
+# The abi-tags file uses a fairly simplistic model for name recognition that
+# can't distinguish i486-pc-linux-gnu fully from i486-pc-gnu.  So we mutate a
+# $host_os of `gnu*' here to be `gnu-gnu*' just so that it can tell.
+# This doesn't get used much beyond that, so it's fairly safe.
+case "$host_os" in
+linux*)
+  ;;
+gnu*)
+  host_os=`echo $host_os | sed -e 's/gnu/gnu-gnu/'`
+  ;;
+esac
+
 # We keep the original values in `$config_*' and never modify them, so we
 # can write them unchanged into config.make.  Everything else uses
 # $machine, $vendor, and $os, and changes them whenever convenient.

configure.ac

@@ -360,6 +360,18 @@ if test "$build_pt_chown" = yes; then
   AC_DEFINE(HAVE_PT_CHOWN)
 fi
 
+# The abi-tags file uses a fairly simplistic model for name recognition that
+# can't distinguish i486-pc-linux-gnu fully from i486-pc-gnu.  So we mutate a
+# $host_os of `gnu*' here to be `gnu-gnu*' just so that it can tell.
+# This doesn't get used much beyond that, so it's fairly safe.
+case "$host_os" in
+linux*)
+  ;;
+gnu*)
+  host_os=`echo $host_os | sed -e 's/gnu/gnu-gnu/'`
+  ;;
+esac
+
 # We keep the original values in `$config_*' and never modify them, so we
 # can write them unchanged into config.make.  Everything else uses
 # $machine, $vendor, and $os, and changes them whenever convenient.