[build] Move gthr to toplevel libgcc

[Paolo Bonzini]

On 08/08/2011 05:42 PM, John David Anglin wrote:
>
>
>> ** _DCE_THREADS is used to select gthr-dce.h, but again dce is the
>> only/default model on hppa[12]*-*-hpux10* (pa-hpux10.h), so the
>> special-casing can be removed.
>
> DCE threads and thread single are both supported.  There are
> multilibs for both.  Different libraries are needed for threaded and
> non threaded programs, and there is no mechanism to detect whether
> threads are active or not.

Rainer used _REENTRANT for that, because it's already in the spec.  Is 
that ok?

Paolo