abi_check build broken

[Loren James Rittle]

> /builds/gcc/misc/i686-suse-linux-gnu/libstdc++-v3/src/.libs/libstdc++.so:
> undefined reference to `pthread_create' [...]
> Why is -lpthread not added anymore?

Hi AJ, it never was added (on ELF platforms) nor should it be (since
no reference to threading functions exist inside that test); something
else broke.  Yup, I see this on ref5 built on 12/7:

[...]/gcc-build-ref5-1208/i386-unknown-freebsd5.2/libstdc++-v3/src/\
.libs/libstdc++.so: undefined reference to `pthread_create'

Mainline (dated Tue Dec 2 00:44:38 GMT 2003) bootstrapped on my
desktop didn't have that issue.  When I updated just libstdc++ and
fully rebuild it with that compiler, it doesn't have that issue.  I am
attempting to compete a quickstrap on my desktop, to see if (more
likely) binutils version related or (more likely) compiler change
between ~12/2 and ~12/7.

As built 12/1 on my desktop with GNU ld version 2.14 20031007:
($ nm /usr/local/beta-gcc/lib/libstdc++.so.6 | grep pthread)
[...]         w pthread_create [...]

As built 12/8 on ref5 with GNU ld version 2.13.2 [FreeBSD] 2002-11-27:
[...]         U pthread_create [...]

The second case is not right but there are too many variable to know
what broke it.  Infer what you might from this information.

Regards,
Loren