ino-map: Improve GCC 11 allocation-deallocation checking

[Bruno Haible]

2021-08-07  Bruno Haible  <bruno@clisp.org>

        ino-map: Improve GCC 11 allocation-deallocation checking.
        * lib/ino-map.h (ino_map_free): Move declaration up.
        (ino_map_alloc): Declare that deallocation must happen through
        'ino_map_free'.

diff --git a/lib/ino-map.h b/lib/ino-map.h
index fb820f7..ea40f37 100644
--- a/lib/ino-map.h
+++ b/lib/ino-map.h
@@ -23,8 +23,13 @@
 
 # define INO_MAP_INSERT_FAILURE ((size_t) -1)
 
-struct ino_map *ino_map_alloc (size_t);
+struct ino_map;
+
 void ino_map_free (struct ino_map *) _GL_ATTRIBUTE_NONNULL ((1));
+
+struct ino_map *ino_map_alloc (size_t)
+  _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_DEALLOC (ino_map_free, 1);
+
 size_t ino_map_insert (struct ino_map *, ino_t) _GL_ATTRIBUTE_NONNULL ((1));
 
 #endif