A Linux/libc 5 patch for egcs 1.1.2

[Jeffrey A Law]

  In message <199902282133.NAA24574@atrus.synopsys.com>you write:
  > I guess I shouldn't be surprised, as we worked hard to make egcs-1.0
  > work right on Red Hat 4.2 (since it was the most common Linux at that
  > time).
Yup.

  > Could you add this as a testcase for the libio testsuite?
That's the plan.

It actually looks like libio has been hacked before to address this exact
issue.  Every function HJ's patch makes weak the code already tries to make
weak, but is failing.

Basically it tests #ifdef weak_alias which isn't defined anywhere in libio
or in include files included by files in libio.

I found its definition in gnu-stabs.h on my RH4.2 box.  Ugh.

We could easily get the same net result by defining weak_alias in a common
header file in libio.  However, I didn't see one that was common, but
internal to libio (we don't want to pollute the namespace).

jeff