[PATCH] libc x86-64 __thread fix

[Roland McGrath]

> Actually, maybe just the #include <tls.h> is needed.

Yes, though that doesn't directly affect the build of the rtld modules.

> The problem was that without including tls.h uname.os etc. in libc-pic.a

Ah, I see.  I was confused as to how it could be losing even if
USE___THREAD was never defined at all, because !defined -> 0 is the right
default for the rtld build.  But that explains it, since it was the libc
build of the module that indirectly loused up the rtld build.

> Though IMHO putting RTLD_PRIVATE_ERRNO case before USE__THREAD
> shouldn't hurt.

Certainly.  I just don't like these things to be mysterious.