libc bump subproject

[Joerg Sonnenberger <joerg@xxxxxxxxxxxxxxxxx>]

Hi all,
just to keep track of what needs to be done for the major bumps,
I'll like to post my TODO list here, others might want to add
tasks.

1. Import citrus code.
- I'll update the patch in the next days to include my latest local
  fixes, there are some minor issues (e.g. for the moment no LC_TIME
  and LC_MONETARY support until I get a clean version ready).
2. Get struct statfs 64bit clean.
- This changes e.g. the ABI of fts(3), but is IMO a necessary thing
  in the medium term anyway. This will be done via a new system call
  to keep the current code running. The old version can be moved into
  a COMPAT_FREEBSD_4 option later.
3. Visibility check for all global symbols.
- I want to verify that no internal global symbols without __libc prefix
  exist and reduce the exported list to the necessary minimum.
- Not started yet, planned for next week.
4. Merge Eirik's sysmessage changes from libcr.
- Maybe combine this with the upper step to get the naming cleaner,
  esp. in combination with the use in the thread libraries.

Joerg