* lib/savedir.c: Include attribute.h.
(direntry_t): The ‘name’ member is now idx_t, not char *,
so that it survives name_space relocation.
(direntry_cmp_name, direntry_cmp_inode, comparison_function):
Adjust to qsort_r API, and to direntry_t layout change.
(streamsavedir): Redo to avoid need for xstrdup on each directory
entry. Instead, copy the string data into name_space; this
typically scales better the memory allocator is called O(log N)
rather than O(N) times. Use qsort_r so that name_space can be
passed to the comparison functions. Simplify calls to ‘free’ so
that lack of leakage is more obvious.
* modules/savedir (Depends-on): Add attribute, qsort_r.