simplify m4/include_next.m4

[Bruno Haible]

This removes a one-year-old FIXME from m4/include_next.m4.

2008-08-29  Bruno Haible  <address@hidden>

        * m4/include_next.m4 (gl_INCLUDE_NEXT): Don't define HAVE_INCLUDE_NEXT
        any more.

--- m4/include_next.m4.orig     Sat Aug 30 02:10:51 2008
+++ m4/include_next.m4  Sat Aug 30 02:09:18 2008
@@ -1,4 +1,4 @@
-# include_next.m4 serial 6
+# include_next.m4 serial 7
 dnl Copyright (C) 2006-2008 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -37,12 +37,6 @@
      rm -rf conftestd1 conftestd2
     ])
   if test $gl_cv_have_include_next = yes; then
-
-    dnl FIXME: Remove HAVE_INCLUDE_NEXT and update everything that uses it
-    dnl to use @INCLUDE_NEXT@ instead.
-    AC_DEFINE([HAVE_INCLUDE_NEXT], 1,
-             [Define if your compiler supports the #include_next directive.])
-
     INCLUDE_NEXT=include_next
   else
     INCLUDE_NEXT=include