Temporary fix for PGI compiler.

config/config.guess

@@ -2,7 +2,7 @@
 # Attempt to guess a canonical system name.
 #   Copyright 1992-2013 Free Software Foundation, Inc.
 
-timestamp='2013-06-10'
+timestamp='2014-08-20'
 
 # This file is free software; you can redistribute it and/or modify it
 # under the terms of the GNU General Public License as published by
@@ -149,7 +149,8 @@ Linux|GNU|GNU/*)
 	LIBC=gnu
 	#endif
 	EOF
-	eval `$CC_FOR_BUILD -E $dummy.c 2>/dev/null | grep '^LIBC'`
+        eval `$CC_FOR_BUILD -E $dummy.c 2>/dev/null \
+          | sed -n 's/^LIBC *= */LIBC=/p'`
 	;;
 esac