FYI: maint: s/UNUSED/_GL_UNUSED/

[Jim Meyering]

I noticed that sed defined its own UNUSED macro.
It's better to use gnulib's _GL_UNUSED:

> From 290c59315b093ed812d6c5f25c570c73e0e4996c Mon Sep 17 00:00:00 2001
From: Jim Meyering <address@hidden>
Date: Fri, 23 Mar 2018 13:26:54 -0700
Subject: [PATCH] maint: remove old definition of UNUSED: use _GL_UNUSED
 instead

* sed/execute.c (UNUSED): Remove macro definition.
(read_always_fail): Use _GL_UNUSED instead.
---
 sed/execute.c | 12 +-----------
 1 file changed, 1 insertion(+), 11 deletions(-)

diff --git a/sed/execute.c b/sed/execute.c
index 453886e..2804c5e 100644
--- a/sed/execute.c
+++ b/sed/execute.c
@@ -37,16 +37,6 @@
 #include "acl.h"
 #include "ignore-value.h"

-#ifdef __GNUC__
-# if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__-0 >= 7)
-   /* silence warning about unused parameter even for "gcc -W -Wunused" */
-#  define UNUSED       __attribute__((unused))
-# endif
-#endif
-#ifndef UNUSED
-# define UNUSED
-#endif
-
 /* The number of extra bytes that must be allocated/usable, beyond
    the declared "end" of each line buffer that may be passed to
    match_regex.  This is imposed by its use of dfaexec.  */
@@ -386,7 +376,7 @@ line_exchange (struct line *a, struct line *b, int state)
 
 /* dummy function to simplify read_pattern_space() */
 static bool
-read_always_fail(struct input *input UNUSED)
+read_always_fail(struct input *input _GL_UNUSED)
 {
   return false;
 }
-- 
2.13.5