Serious v3 shared library bug

[Jason Merrill <jason at redhat dot com>]

I discovered recently that linking against shared v3, even if I don't use
any of the C++ library bits, suppresses the usual flush of the standard
files on exit().  Testcase:

  #include <stdio.h>
  int main () { printf ("Hi\n"); }

Compile that, link against shared v3 and run it with

  ./a.out|cat

to see the problem.  Running it without redirection works fine, presumably
because output to a tty is not buffered.  static v3 does not have this
problem.

Any ideas?

Jason