merge changes from src/lib/libc/gen/fts.c:
1.35:
 Ensure fts_close() doesn't spuriously close fd 0,
 by testing FTS_SYMFOLLOW in fts_flags instead of fts_options.
 Fix provided by Ben Harris in PR 40319
1.37:
 Fix sign-compare issue
1.38:
 Avoid possible integer overflow and subsequent collateral damage.
 Received from OpenBSD via US-CERT as VU #590371.


(lukem)