pdb: _bfd_generic_close_and_cleanup

Every format that might appear inside a generic archive needs to call
_bfd_generic_close_and_cleanup, so that the archive element lookup
htab can be tidied on closing an element.  Otherwise you get stale
entries in the htab pointing at freed and perhaps reused memory,
resulting in segfaults when the archive is closed.

Calling _bfd_generic_close_and_cleanup on close means tdata needs to
be set up too, since pdb claims to be of format bfd_archive.

	* pdb.c (pdb_close_and_cleanup): Define as
	_bfd_generic_close_and_cleanup.
	(pdb_archive_p): Set up tdata for bfd_archive format.

bfd/pdb.c

@@ -54,6 +54,11 @@ pdb_archive_p (bfd *abfd)
       return NULL;
     }
 
+  void *tdata = bfd_zalloc (abfd, sizeof (struct artdata));
+  if (tdata == NULL)
+    return NULL;
+  bfd_ardata (abfd) = tdata;
+
   return _bfd_no_cleanup;
 }
 
@@ -755,7 +760,7 @@ pdb_write_contents (bfd *abfd)
 #define pdb_new_section_hook _bfd_generic_new_section_hook
 #define pdb_get_section_contents _bfd_generic_get_section_contents
 #define pdb_get_section_contents_in_window _bfd_generic_get_section_contents_in_window
-#define pdb_close_and_cleanup _bfd_bool_bfd_true
+#define pdb_close_and_cleanup _bfd_generic_close_and_cleanup
 
 #define pdb_slurp_armap _bfd_noarchive_slurp_armap
 #define pdb_slurp_extended_name_table _bfd_noarchive_slurp_extended_name_table