What to do about gnulib libio dependencies?

[Florian Weimer]

gnulib has a few modules which touch libio internals which aren't really 
exported:

fbufmode
freadahead
freadptr
freadseek
fseterr

This is a problem because it is not apparent from the glibc sources that 
the implementation details used by these functions are actually used 
externally.

Should we just add these functions to glibc?  In some cases, the 
interactions with wide oriented streams could be problematic.

Thanks,
Florian