[Patch] Fix libstdc++/9507

[Paolo Carlini]

Pétur Runólfsson wrote:

>On second thought, this probably isn't correct, I don't think open
>is required to call seekoff, it might for example call fseek directly.
>
Well, for sure v3 implementation of open calls it!

>If you are changing filebuf_members.cc, you might want to remove the
>exit(0); at the end of test04 - it seems that test05 is never run :-)
>
Yes ;) Thanks!

Paolo.