use the saved value if mtime_set is already set (intended
for archive files, though apparently not used yet).
+Wed Dec 4 02:00:30 1991 John Gilmore (gnu at cygnus.com)
+
+ * bfd.c (bfd_get_mtime): Don't cache mtime any more; only
+ use the saved value if mtime_set is already set (intended
+ for archive files, though apparently not used yet).
+
Tue Dec 3 22:54:50 1991 John Gilmore (gnu at cygnus.com)
* targets.c: Revise comments about how to configure the target