[PATCH] PPC linuxthreads tls.h fix

[Roland McGrath]

> I'm not at all fussed over what you do with the TCB.  Since our tls
> abi has the thread pointer relative to the end of the TCB, you can
> change what's in TCB and its size, and binutils and gcc won't be
> affected.  Perhaps our ABI document shouldn't even mention the size
> of the TCB.

He is talking about the words the thread register points to, i.e. the
word(s) after the DTV pointer.  This is what the TLS document calls the TCB
in "variant I" (TLS_DTV_AT_TP).  Statically laid-out TLS offsets begin
immediately after this.