[3/10] introduce psymtab users

[Doug Evans]

On Wed, Apr 25, 2012 at 11:21 AM, Tom Tromey <tromey@redhat.com> wrote:
> @@ -165,6 +169,11 @@ partial_map_symtabs_matching_filename (struct objfile *objfile,
>
>   ALL_OBJFILE_PSYMTABS_REQUIRED (objfile, pst)
>   {
> +    /* We can skip shared psymtabs here, because any file name will be
> +       attached to the unshared psymtab.  */
> +    if (pst->users != NULL)
> +      continue;
> +
>     if (FILENAME_CMP (name, pst->filename) == 0
>        || (!is_abs && compare_filenames_for_search (pst->filename,
>                                                     name, name_len)))

The abstraction feels broken if ALL_OBJFILE_PSYMTABS* includes these
special shared psymtabs.

[This is akin to the objfile list including separate debug file objfiles.]