[v3] alpha/powerpc/x86 parity for 27_io

[Loren James Rittle]

> ...this fixes the extraneous fails on non-x86 targets. I've tested on
> powerpc, and it fixes it there. I expect the same results on
> alpha. I'll soon see from gcc-testresults.

> Loren, this should fix it, please give it a go.

I see that Mark already approved it and that it is in already.  But,
for the record, I can confirm that parity is now reached for
alpha-unknown-freebsd4.2 and i386-unknown-freebsd4.2.  In particular,
zero FAILs and one XPASS (26_numerics/c99_classification_macros_c.cc).

Have fun surfing. ;-)  Well deserved!

Regards,
Loren