[build] Move gthr to toplevel libgcc

[Paolo Bonzini]

On 08/08/2011 05:51 PM, Rainer Orth wrote:
>>>     libgfortran/acinclude.m4 (LIBGFOR_GTHREAD_WEAK) tries to determine a
>>>      sensible value.
>>
>>  I think libgfortran's approach is the nicest to be added in
>>  libgcc/configure.ac.
>
> I'm not convinced: when it was introduced (or used more extensively), I
> was already bitten by the fact that the GTHREAD_USE_WEAK test uses a
> hardcoded list, instead of really checking what it is meant to test:
> support for weak definitions.  Perhaps the autoconf-archive macro is
> better in this respect.

I was talking in general about the approach, not the implementation. :)

Paolo